Weiping Tang

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Name: Tang, Weiping
Organization: University of Wisconsin , USA
Department: School of Pharmacy
Title: Associate(PhD)

TOPICS

Co-reporter:Wei Zhang, Suqing Zheng, Na Liu, Jenny B. Werness, Ilia A. Guzei and Weiping Tang
Journal of the American Chemical Society March 24, 2010 Volume 132(Issue 11) pp:3664-3665
Publication Date(Web):March 1, 2010
DOI:10.1021/ja100173w
A catalytic enantioselective syn-1,4-bromolactonization of conjugated (Z)-enynes was reported. Diastereomeric ratios >20:1 and up to 99% enantiomeric excesses were observed. Di-, tri-, and tetra-substituted bromoallenes were prepared together with lactone heterocycles efficiently and stereoselectively. Preliminary investigations suggest that the chiral catalyst may serve as a bifunctional reagent by interacting with both a carboxylic acid nucleophile and NBS electrophile.
Co-reporter:Wangze Song;Stephanie A. Blaszczyk;Jitian Liu;Shuojin Wang
Organic & Biomolecular Chemistry 2017 vol. 15(Issue 36) pp:7490-7504
Publication Date(Web):2017/09/20
DOI:10.1039/C7OB01000A
In carbonylative benzannulations, feedstock carbon monoxide is converted to a benzene ring, which is one of the most fundamentally important and common rings in natural products and pharmaceutical compounds. Carbon monoxide, however, is rather inert in the absence of transition metals. Historically, carbonylative benzannulations have been mediated by stoichiometric chromium and iron in the form of Fischer carbenes. Recently, a number of transition metal-catalyzed carbonylative benzannulations have been developed, and almost all of them involve rhodium catalysts. This review will briefly discuss the mechanism and applications of carbonylative benzannulations involving Fischer carbenes and compare them with the more recent transition metal-catalyzed processes, including [3 + 2 + 1] cycloadditions, [5 + 1] cycloadditions, and other less common cycloadditions.
Co-reporter:Wangze Song;John C. Lynch;Xing-zhong Shu
Advanced Synthesis & Catalysis 2016 Volume 358( Issue 12) pp:2007-2011
Publication Date(Web):
DOI:10.1002/adsc.201600196
Co-reporter:Wangze Song, Xiaoxun Li, Ka Yang, Xian-liang Zhao, Daniel A. Glazier, Bao-min Xi, and Weiping Tang
The Journal of Organic Chemistry 2016 Volume 81(Issue 7) pp:2930-2942
Publication Date(Web):March 10, 2016
DOI:10.1021/acs.joc.6b00212
Polycyclic aromatic compounds are important constituents of pharmaceuticals and other materials. We have developed a series of Rh-catalyzed tandem carbonylative benzannulations for the synthesis of tri-, tetra-, and pentacyclic heterocycles from different types of aryl propargylic alcohols. These tandem reactions provide efficient access to highly substituted carbazoles, furocarbazoles, pyrrolocarbazoles, thiophenocarbazoles, and indolocarbazoles. While tricyclic heterocycles could be derived from vinyl aryl propargylic alcohols, tetra- and pentacyclic heterocycles were synthesized from diaryl propargylic alcohols. The tandem carbonylative benzannulation is initiated by a π-acidic rhodium(I) catalyst-mediated nucleophilic addition to alkyne to generate a key metal-carbene intermediate, which is then trapped by carbon monoxide to form a ketene species for 6π electrocyclization. Overall, three bonds and two rings are formed in all of these tandem carbonylative benzannulation reactions.
Co-reporter:Wangze Song, Yu Zhao, John C. Lynch, Hyunjin Kim and Weiping Tang  
Chemical Communications 2015 vol. 51(Issue 98) pp:17475-17478
Publication Date(Web):13 Oct 2015
DOI:10.1039/C5CC07787G
All eight possible stereoisomers of 2,3,6-trideoxyhexopyranosides are prepared systematically from furan derivatives by a sequence of Achmatowicz rearrangement, Pd-catalysed glycosidation, and chiral catalyst-controlled tandem reductions. This sequence provides access to all possible stereoisomers of naturally occurring rhodinopyranosides, amicetopyranosides, disaccharide narbosine B, and other unnatural oligomeric 2,3,6-trideoxyhexopyranosides. It comprises a unique and systematic strategy for the de novo synthesis of deoxysugars.
Co-reporter:Wangze Song, Bao-min Xi, Ka Yang, Weiping Tang
Tetrahedron 2015 Volume 71(Issue 35) pp:5979-5984
Publication Date(Web):2 September 2015
DOI:10.1016/j.tet.2015.04.039
Highly substituted tropones are prepared from cycloheptatrienes derived from Rh-catalyzed intermolecular [5+2] cycloaddition of 3-acyloxy-1,4-enynes and propargylic alcohols. The intermolecular [5+2] cycloaddition is highly regioselective for a variety of propargylic alcohols. Elimination of the cycloaddition products afforded various substituted tropones.
Co-reporter:Gabrielle N. Winston-McPherson;Dr. Weiping Tang
ChemCatChem 2015 Volume 7( Issue 4) pp:574-576
Publication Date(Web):
DOI:10.1002/cctc.201402915
Co-reporter:Hui Li, Xiaoxun Li, Hao-Yuan Wang, Gabrielle N. Winston-McPherson, Hao-miao Julie Geng, Ilia A. Guzei and Weiping Tang  
Chemical Communications 2014 vol. 50(Issue 82) pp:12293-12296
Publication Date(Web):02 Sep 2014
DOI:10.1039/C4CC05901H
Various highly substituted 2,3′-diindolylmethane heterocycles were prepared from propargylic alcohols and indole nucleophiles via a transition metal-catalyzed tandem indole annulation/arylation reaction for the first time. Among the metal catalysts we examined, the most economical copper(I) catalyst provided the highest efficiency. The indole nucleophiles could also be replaced by other electron-rich arenes or alcohols.
Co-reporter:Dr. Suqing Zheng;Casi M. Schienebeck;Dr. Wei Zhang;Hao-Yuan Wang;Dr. Weiping Tang
Asian Journal of Organic Chemistry 2014 Volume 3( Issue 4) pp:366-376
Publication Date(Web):
DOI:10.1002/ajoc.201400030

Abstract

Naturally occurring cinchona alkaloids include quinine, quinidine, cinchonine, and cinchonidine. Many of their derivatives are also readily available. This Focus Review summarizes recent applications of cinchona alkaloid derivatives, an important class of organocatalysts, in enantioselective halofunctionalization of alkenes and alkynes. Most successful examples in this area are intramolecular halofunctionalizations, where the nucleophile is tethered with the alkene or alkyne substrate. Only a few catalytic enantioselective intermolecular halofunctionalization of alkenes have been realized. Dimeric cinchona alkaloids are the most frequently used catalysts in asymmetric halofunctionalizations. Most other catalysts have an appended functional group on the C9 position of the cinchona alkaloids. These functional groups include (thio)urea, thiocarbamate, and sulfonamides.

Co-reporter:Gabrielle N. Winston-McPherson, Dongxu Shu, Weiping Tang
Bioorganic & Medicinal Chemistry Letters 2014 24(16) pp: 4023-4025
Publication Date(Web):
DOI:10.1016/j.bmcl.2014.06.009
Co-reporter:Na Liu, Wangze Song, Casi M. Schienebeck, Min Zhang, Weiping Tang
Tetrahedron 2014 70(49) pp: 9281-9305
Publication Date(Web):
DOI:10.1016/j.tet.2014.07.065
Co-reporter:Xiaoxun Li ; Wangze Song
Journal of the American Chemical Society 2013 Volume 135(Issue 45) pp:16797-16800
Publication Date(Web):October 28, 2013
DOI:10.1021/ja408829y
A Rh-catalyzed tandem annulation and (5 + 1) cycloaddition was realized. 3-Hydroxy-1,4-enyne served as the new 5-carbon component for the (5 + 1) cycloaddition. Substituted carbazoles, dibenzofurans, and tricyclic compounds containing a cyclohexadienone moiety could be prepared efficiently. The identification of a byproduct suggests that metal carbene and ketene intermediates may be involved in the (5 + 1) cycloaddition.
Co-reporter:Xiufang Xu ; Peng Liu ; Xing-zhong Shu ; Weiping Tang ;K. N. Houk
Journal of the American Chemical Society 2013 Volume 135(Issue 25) pp:9271-9274
Publication Date(Web):May 31, 2013
DOI:10.1021/ja4036785
The mechanism of Rh-catalyzed (5+2) cycloadditions of 3-acyloxy-1,4-enyne (ACE) and alkynes is investigated using density functional theory calculations. The catalytic cycle involves 1,2-acyloxy migration, alkyne insertion, and reductive elimination to form the cycloheptatriene product. In contrast to the (5+2) cycloadditions with vinylcyclopropanes (VCPs), in which alkyne inserts into a rhodium–allyl bond, alkyne insertion into a Rh–C(sp2) bond is preferred. The 1,2-acyloxy migration is found to be the rate-determining step of the catalytic cycle. The electron-rich p-dimethylaminobenzoate substrate promotes 1,2-acyloxy migration and significantly increases the reactivity. In the regioselectivity-determining alkyne insertion step, the alkyne substituent prefers to be distal to the forming C–C bond and thus distal to the OAc group in the product.
Co-reporter:Min Zhang ; Na Liu
Journal of the American Chemical Society 2013 Volume 135(Issue 33) pp:12434-12438
Publication Date(Web):July 25, 2013
DOI:10.1021/ja406255j
The tetracyclic carbon skeleton of hainanolidol and harringtonolide was efficiently constructed by an intramolecular oxidopyrylium-based [5 + 2] cycloaddition. An anionic ring-opening strategy was developed for the cleavage of the ether bridge in 8-oxabicyclo[3.2.1]octenes derived from the [5 + 2] cycloaddition. Conversion of cycloheptadiene to tropone was realized by a sequential [4 + 2] cycloaddition, Kornblum–DeLaMare rearrangement, and double elimination. The biomimetic synthesis of harringtonolide from hainanolidol was also confirmed.
Co-reporter:Renhe Liu ; Gabrielle N. Winston-McPherson ; Zhong-Yue Yang ; Xin Zhou ; Wangze Song ; Ilia A. Guzei ; Xiufang Xu
Journal of the American Chemical Society 2013 Volume 135(Issue 22) pp:8201-8204
Publication Date(Web):May 23, 2013
DOI:10.1021/ja4047069
Rh(I) carbenes were conveniently generated from readily available ynamides. These metal carbene intermediates could undergo metathesis with electron-rich or neutral alkynes to afford 2-oxopyrrolidines or be trapped by tethered alkenes to yield 3-azabicyclo[3.1.0]hexanes, a common skeleton in numerous bioactive pharmaceuticals. Although the scope of the former is limited, the latter reaction tolerates various substituted alkenes.
Co-reporter:Wei Zhang, Na Liu, Casi M. Schienebeck, Xin Zhou, Izarin I. Izhar, Ilia A. Guzei and Weiping Tang  
Chemical Science 2013 vol. 4(Issue 6) pp:2652-2656
Publication Date(Web):08 Apr 2013
DOI:10.1039/C3SC50446H
Highly enantioselective intermolecular bromoesterification of alkenes was achieved for the first time. Both C–O and C–Br bonds were introduced enantioselectively in this olefin addition reaction. The sulfonamide NH directing group is important for both the reactivity and enantioselectivity.
Co-reporter:Renhe Liu, Min Zhang, Gabrielle Winston-McPherson and Weiping Tang  
Chemical Communications 2013 vol. 49(Issue 39) pp:4376-4378
Publication Date(Web):24 Jul 2012
DOI:10.1039/C2CC34609E
Regioselective ring expansion of alkynyl cyclopropanes to highly substituted cyclobutenes was developed. The reaction involves a copper-catalyzed cycloaddition of an alkyne with an arylsulfonyl azide and a silver-catalyzed carbene formation followed by ring expansion of a cyclopropyl carbene intermediate.
Co-reporter:Casi M. Schienebeck, Patrick J. Robichaux, Xiaoxun Li, Lianqing Chen and Weiping Tang  
Chemical Communications 2013 vol. 49(Issue 26) pp:2616-2618
Publication Date(Web):11 Feb 2013
DOI:10.1039/C3CC40634B
We systematically examined the effect of different esters on the rhodium-catalyzed intermolecular [5+2] cycloaddition of 3-acyloxy-1,4-enynes and alkynes with a concomitant 1,2-acyloxy migration. Significant rate acceleration was observed for benzoate substrates bearing an electron-donating substituent. The cycloaddition can now be conducted under much more practical conditions for most terminal alkynes.
Co-reporter:Dongxu Shu, Gabrielle N. Winston-McPherson, Wangze Song, and Weiping Tang
Organic Letters 2013 Volume 15(Issue 16) pp:4162-4165
Publication Date(Web):August 5, 2013
DOI:10.1021/ol4018408
Various diindolylmethanes were prepared from propargylic ethers and substituted indoles via a platinum-catalyzed tandem indole annulation/arylation cascade. The resulting diindolylmethanes could be converted to natural product malassezin by formylation or indolo[3,2-b]carbazoles by cyclization.
Co-reporter:Na Liu;Hao-Yuan Wang;Wei Zhang;Zhi-Hong Jia;Ilia A. Guzei;Hua-dong Xu
Chirality 2013 Volume 25( Issue 11) pp:805-809
Publication Date(Web):
DOI:10.1002/chir.22219

ABSTRACT

Halocyclization of alkenes was realized using N-acylhemiaminal nucleophiles. High diastereoselectivity could be achieved for the formation of three stereogenic centers in this halogen-mediated cyclization reaction. We also demonstrated that enantioselective bromocyclization of alkenes using N-acylhemiaminal nucleophiles was possible. Chirality 25:805–809, 2013. © 2013 Wiley Periodicals, Inc.

Co-reporter:Dongxu Shu;Wangze Song;Xiaoxun Li;Dr. Weiping Tang
Angewandte Chemie 2013 Volume 125( Issue 11) pp:3319-3322
Publication Date(Web):
DOI:10.1002/ange.201209266
Co-reporter:Dr. Xing-zhong Shu;Casi M. Schienebeck;Wangze Song;Dr. Ilia A. Guzei;Dr. Weiping Tang
Angewandte Chemie 2013 Volume 125( Issue 51) pp:13846-13850
Publication Date(Web):
DOI:10.1002/ange.201306919
Co-reporter:Dongxu Shu;Wangze Song;Xiaoxun Li;Dr. Weiping Tang
Angewandte Chemie International Edition 2013 Volume 52( Issue 11) pp:3237-3240
Publication Date(Web):
DOI:10.1002/anie.201209266
Co-reporter:Dr. Xing-zhong Shu;Casi M. Schienebeck;Wangze Song;Dr. Ilia A. Guzei;Dr. Weiping Tang
Angewandte Chemie International Edition 2013 Volume 52( Issue 51) pp:13601-13605
Publication Date(Web):
DOI:10.1002/anie.201306919
Co-reporter:Xing-Zhong Shu, Dongxu Shu, Casi M. Schienebeck and Weiping Tang  
Chemical Society Reviews 2012 vol. 41(Issue 23) pp:7698-7711
Publication Date(Web):15 Aug 2012
DOI:10.1039/C2CS35235D
Transition metal-catalyzed acyloxy migration of propargylic esters offers versatile entries to allene and vinyl carbene intermediates for various fascinating subsequent transformations. Most π-acidic metals (e.g. gold and platinum) are capable of facilitating these acyloxy migration events. However, very few of these processes involve redox chemistry, which are well-known for most other transition metals such as rhodium. The coupling of acyloxy migration of propargylic esters with oxidative addition, migratory insertion, and reductive elimination may lead to ample new opportunities for the design of new reactions. This tutorial review summarizes recent developments in Rh-catalyzed 1,3- and 1,2-acyloxy migration of propargylic esters in a number of cycloaddition reactions. Related Au- and Pt-catalyzed cycloadditions involving acyloxy migration are also discussed.
Co-reporter:Xing-Zhong Shu, Xiaoxun Li, Dongxu Shu, Suyu Huang, Casi M. Schienebeck, Xin Zhou, Patrick J. Robichaux, and Weiping Tang
Journal of the American Chemical Society 2012 Volume 134(Issue 11) pp:5211-5221
Publication Date(Web):February 26, 2012
DOI:10.1021/ja2109097
A new type of rhodium-catalyzed [5 + 2] cycloaddition was developed for the synthesis of seven-membered rings with diverse functionalities. The ring formation was accompanied by a 1,2-acyloxy migration event. The five- and two-carbon components of the cycloaddition are 3-acyloxy-1,4-enynes (ACEs) and alkynes, respectively. Cationic rhodium(I) catalysts worked most efficiently for the intramolecular cycloaddition, while only neutral rhodium(I) complexes could facilitate the intermolecular reaction. In both cases, electron-poor phosphite or phosphine ligands often improved the efficiency of the cycloadditions. The scope of ACEs and alkynes was investigated in both the intra- and intermolecular reactions. The resulting seven-membered-ring products have three double bonds that could be selectively functionalized.
Co-reporter:Min Zhang and Weiping Tang
Organic Letters 2012 Volume 14(Issue 14) pp:3756-3759
Publication Date(Web):July 11, 2012
DOI:10.1021/ol301614v
The cyclohexenone core of welwitindolinones was synthesized by a Rh(I)-catalyzed [5 + 1]-cycloaddition of an allenylcyclopropane with CO. A pentasubstituted cyclopropane was prepared successfully by a Rh(II)-catalyzed intramolecular cyclopropanation of alkenes with chlorodiazoacetates.
Co-reporter:Suyu Huang, Xiaoxun Li, Claire L. Lin, Ilia A. Guzei and Weiping Tang  
Chemical Communications 2012 vol. 48(Issue 16) pp:2204-2206
Publication Date(Web):04 Jan 2012
DOI:10.1039/C2CC17406E
A Rh-catalyzed 1,3-acyloxy migration of propargyl ester followed by intramolecular [4+2] cycloaddition of vinylallene and unactivated alkyne was developed. This tandem reaction provides access to bicyclic compounds containing a highly functionalized isotoluene or cyclohexenone structural motif, while only aromatic compounds were observed in related transition metal-catalyzed cycloadditions.
Co-reporter:Dongxu Shu, Xiaoxun Li, Min Zhang, Patrick J. Robichaux, Ilia A. Guzei, and Weiping Tang
The Journal of Organic Chemistry 2012 Volume 77(Issue 15) pp:6463-6472
Publication Date(Web):July 13, 2012
DOI:10.1021/jo300973r
We have developed two different types of tandem reactions for the synthesis of highly functionalized cyclohexenones from cyclopropyl substituted propargyl esters. Both reactions were initiated by rhodium-catalyzed Saucy–Marbet 1,3-acyloxy migration. The resulting cyclopropyl substituted allenes derived from acyloxy migration then underwent [5 + 1] cycloaddition with CO. The acyloxy group not only eased the access to allene intermediates but also provided a handle for further selective functionalizations.
Co-reporter:Wei Zhang;Na Liu;Casi M. Schienebeck;Kyle Decloux;Dr. Suqing Zheng;Jenny B. Werness;Dr. Weiping Tang
Chemistry - A European Journal 2012 Volume 18( Issue 23) pp:7296-7305
Publication Date(Web):
DOI:10.1002/chem.201103809

Abstract

New organocatalysts have been developed for the enantioselective halolactonization of (Z)-1,3-enynes and 1,1-disubstituted alkenes. In the case of 1,3-enynes, the carboxylate nucleophile and halogen electrophile were added to the conjugated π-system from the same face. Up to 99 % ee was achieved for the 1,4-syn-bromolactonization of conjugated (Z)-1,3-enynes. Based on the results from the enyne halolactonization, a second generation of catalysts was designed for simple olefins. Up to 91 % ee was observed for chlorolactonization of 1,1-disubstituted alkenes. The catalysts developed for the enantioselective halolactonization of both enynes and alkenes are composed of a cinchona alkaloid skeleton tethered to a urea group.

Co-reporter:Renhe Liu;Dr. Min Zhang;Thomas P. Wyche;Gabrielle N. Winston-McPherson;Dr. Tim S. Bugni ;Dr. Weiping Tang
Angewandte Chemie International Edition 2012 Volume 51( Issue 30) pp:7503-7506
Publication Date(Web):
DOI:10.1002/anie.201203379
Co-reporter:Renhe Liu;Dr. Min Zhang;Thomas P. Wyche;Gabrielle N. Winston-McPherson;Dr. Tim S. Bugni ;Dr. Weiping Tang
Angewandte Chemie 2012 Volume 124( Issue 30) pp:7621-7624
Publication Date(Web):
DOI:10.1002/ange.201203379
Co-reporter:Na Liu, Casi M. Schienebeck, Michelle D. Collier, Weiping Tang
Tetrahedron Letters 2011 Volume 52(Issue 47) pp:6217-6219
Publication Date(Web):23 November 2011
DOI:10.1016/j.tetlet.2011.09.057
Electrophilic halogen can promote either halocyclization or Overman rearrangement of allylic trichloroacetimidates. We found that the chemoselectivity was dependent on the nature of the halogenation reagents for primary allylic trichloroacetimidates. A one-pot procedure was developed for the preparation of allylic trichloroacetamides directly from allylic alcohols at room temperature.
Co-reporter:Na Liu, Jenny B. Werness, Ilia A. Guzei, Weiping Tang
Tetrahedron 2011 67(24) pp: 4385-4390
Publication Date(Web):
DOI:10.1016/j.tet.2011.02.039
Co-reporter:Jenny B. Werness
Science China Chemistry 2011 Volume 54( Issue 1) pp:56-60
Publication Date(Web):2011 January
DOI:10.1007/s11426-010-4133-6
The discovery of the novel reactivity of conjugated enynes, mediated by readily available halogenation reagents, opens a broad range of mechanistically unique pathways for the synthesis of highly functionalized chiral allene derivatives. Bromoallenyl pyrrolidines can be synthesized via 1,4-addition of sulfonamide nitrogen nucleophiles and halogens to conjugated enynes. This process can lead to simultaneous formation of a highly functionalized axially chiral allene and a stereogenic center under economical and environmentally friendly reaction conditions.
Co-reporter:Dr. Xing-zhong Shu;Suyu Huang;Dongxu Shu;Ilia A. Guzei;Dr. Weiping Tang
Angewandte Chemie International Edition 2011 Volume 50( Issue 35) pp:8153-8156
Publication Date(Web):
DOI:10.1002/anie.201103136
Co-reporter:Dongxu Shu;Xiaoxun Li;Dr. Min Zhang;Patrick J. Robichaux;Dr. Weiping Tang
Angewandte Chemie 2011 Volume 123( Issue 6) pp:1382-1385
Publication Date(Web):
DOI:10.1002/ange.201006881
Co-reporter:Dr. Xing-zhong Shu;Suyu Huang;Dongxu Shu;Ilia A. Guzei;Dr. Weiping Tang
Angewandte Chemie 2011 Volume 123( Issue 35) pp:8303-8306
Publication Date(Web):
DOI:10.1002/ange.201103136
Co-reporter:Xiaoxun Li;Dr. Min Zhang;Dongxu Shu;Patrick J. Robichaux;Suyu Huang;Dr. Weiping Tang
Angewandte Chemie 2011 Volume 123( Issue 44) pp:10605-10608
Publication Date(Web):
DOI:10.1002/ange.201104861
Co-reporter:Dongxu Shu;Xiaoxun Li;Dr. Min Zhang;Patrick J. Robichaux;Dr. Weiping Tang
Angewandte Chemie International Edition 2011 Volume 50( Issue 6) pp:1346-1349
Publication Date(Web):
DOI:10.1002/anie.201006881
Co-reporter:Xiaoxun Li;Dr. Min Zhang;Dongxu Shu;Patrick J. Robichaux;Suyu Huang;Dr. Weiping Tang
Angewandte Chemie International Edition 2011 Volume 50( Issue 44) pp:10421-10424
Publication Date(Web):
DOI:10.1002/anie.201104861
Co-reporter:Joann M. Um ; Huadong Xu ; K. N. Houk
Journal of the American Chemical Society 2009 Volume 131(Issue 19) pp:6664-6665
Publication Date(Web):April 29, 2009
DOI:10.1021/ja9016446
The thermal ring-opening reactions of 4-phenyl-1,3,3-triethoxycarbonylcyclobutene and 4-methyl-1,3,3-triethoxycarbonylcyclobutene yield dienes that result from an unexpected selectivity for “inward” rotation of the phenyl and methyl groups. With 1-ethoxycarbonyl-4-phenylcyclobutene, “outward” rotation of the phenyl group occurs exclusively. Density functional theory was used to investigate the role of the 3,3-geminal diester groups and the origin of torquoselectivity in these electrocyclic reactions. The rules of torquoselectivity still hold, with a calculated 6−8 kcal/mol preference for outward rotation of the methyl and phenyl substituents. However, cyclization of the “out” dienes to pyran intermediates allows for isomerization and thermodynamic control of stereoselectivity.
Co-reporter:Wen Zhang, Jenny B. Werness, Weiping Tang
Tetrahedron 2009 65(16) pp: 3090-3095
Publication Date(Web):
DOI:10.1016/j.tet.2008.09.045
Co-reporter:Huadong Xu Dr.;Wen Zhang Dr.;Dongxu Shu;JennyB. Werness Dr.
Angewandte Chemie International Edition 2008 Volume 47( Issue 46) pp:8933-8936
Publication Date(Web):
DOI:10.1002/anie.200803910
Co-reporter:Huadong Xu Dr.;Wen Zhang Dr.;Dongxu Shu;JennyB. Werness Dr.
Angewandte Chemie 2008 Volume 120( Issue 46) pp:9065-9068
Publication Date(Web):
DOI:10.1002/ange.200803910
Co-reporter:Wei Zhang ; Suqing Zheng ; Na Liu ; Jenny B. Werness ; Ilia A. Guzei
Journal of the American Chemical Society () pp:
Publication Date(Web):March 1, 2010
DOI:10.1021/ja100173w
A catalytic enantioselective syn-1,4-bromolactonization of conjugated (Z)-enynes was reported. Diastereomeric ratios >20:1 and up to 99% enantiomeric excesses were observed. Di-, tri-, and tetra-substituted bromoallenes were prepared together with lactone heterocycles efficiently and stereoselectively. Preliminary investigations suggest that the chiral catalyst may serve as a bifunctional reagent by interacting with both a carboxylic acid nucleophile and NBS electrophile.
Co-reporter:Xiaoxun Li ; Suyu Huang ; Casi M. Schienebeck ; Dongxu Shu
Organic Letters () pp:
Publication Date(Web):March 2, 2012
DOI:10.1021/ol300330t
Functionalized cyclopentenones were synthesized by a Rh-catalyzed carbonylation of 3-acyloxy-1,4-enynes, derived from alkynes and α,β-unsaturated aldehydes. The reaction involved a Saucy–Marbet 1,3-acyloxy migration of propargyl esters and a [4 + 1] cycloaddition of the resulting acyloxy substituted vinylallene with CO.
Co-reporter:Xing-Zhong Shu, Dongxu Shu, Casi M. Schienebeck and Weiping Tang
Chemical Society Reviews 2012 - vol. 41(Issue 23) pp:NaN7711-7711
Publication Date(Web):2012/08/15
DOI:10.1039/C2CS35235D
Transition metal-catalyzed acyloxy migration of propargylic esters offers versatile entries to allene and vinyl carbene intermediates for various fascinating subsequent transformations. Most π-acidic metals (e.g. gold and platinum) are capable of facilitating these acyloxy migration events. However, very few of these processes involve redox chemistry, which are well-known for most other transition metals such as rhodium. The coupling of acyloxy migration of propargylic esters with oxidative addition, migratory insertion, and reductive elimination may lead to ample new opportunities for the design of new reactions. This tutorial review summarizes recent developments in Rh-catalyzed 1,3- and 1,2-acyloxy migration of propargylic esters in a number of cycloaddition reactions. Related Au- and Pt-catalyzed cycloadditions involving acyloxy migration are also discussed.
Co-reporter:Hui Li, Xiaoxun Li, Hao-Yuan Wang, Gabrielle N. Winston-McPherson, Hao-miao Julie Geng, Ilia A. Guzei and Weiping Tang
Chemical Communications 2014 - vol. 50(Issue 82) pp:NaN12296-12296
Publication Date(Web):2014/09/02
DOI:10.1039/C4CC05901H
Various highly substituted 2,3′-diindolylmethane heterocycles were prepared from propargylic alcohols and indole nucleophiles via a transition metal-catalyzed tandem indole annulation/arylation reaction for the first time. Among the metal catalysts we examined, the most economical copper(I) catalyst provided the highest efficiency. The indole nucleophiles could also be replaced by other electron-rich arenes or alcohols.
Co-reporter:Hao-Yuan Wang, Wei Zhang, Casi M. Schienebeck, Scott R. Bennett and Weiping Tang
Inorganic Chemistry Frontiers 2014 - vol. 1(Issue 4) pp:
Publication Date(Web):
DOI:10.1039/C3QO00088E
Co-reporter:Ji-tian Liu, Truman J. Do, Christopher J. Simmons, John C. Lynch, Wen Gu, Zhi-Xiong Ma, Wei Xu and Weiping Tang
Organic & Biomolecular Chemistry 2016 - vol. 14(Issue 38) pp:NaN8930-8930
Publication Date(Web):2016/09/12
DOI:10.1039/C6OB01657J
We have developed a versatile synthetic strategy for the synthesis of the natural product diptoindonesin G and its analogues as selective modulators of estrogen receptors. The strategy involves a regioselective dehydrative cyclization of arylacetals, a regioselective bromination of benzofurans, a sequential cross-coupling of bromo-benzofurans with aryl boronic acids, and a BBr3-mediated tandem cyclization and demethylation. Preliminary biological studies uncovered the critical and dispensable phenolic hydroxyl groups in the natural product and also revealed unexpected selectivity for isoforms of estrogen receptor.
Co-reporter:Wei Zhang, Na Liu, Casi M. Schienebeck, Xin Zhou, Izarin I. Izhar, Ilia A. Guzei and Weiping Tang
Chemical Science (2010-Present) 2013 - vol. 4(Issue 6) pp:NaN2656-2656
Publication Date(Web):2013/04/08
DOI:10.1039/C3SC50446H
Highly enantioselective intermolecular bromoesterification of alkenes was achieved for the first time. Both C–O and C–Br bonds were introduced enantioselectively in this olefin addition reaction. The sulfonamide NH directing group is important for both the reactivity and enantioselectivity.
Co-reporter:Suyu Huang, Xiaoxun Li, Claire L. Lin, Ilia A. Guzei and Weiping Tang
Chemical Communications 2012 - vol. 48(Issue 16) pp:NaN2206-2206
Publication Date(Web):2012/01/04
DOI:10.1039/C2CC17406E
A Rh-catalyzed 1,3-acyloxy migration of propargyl ester followed by intramolecular [4+2] cycloaddition of vinylallene and unactivated alkyne was developed. This tandem reaction provides access to bicyclic compounds containing a highly functionalized isotoluene or cyclohexenone structural motif, while only aromatic compounds were observed in related transition metal-catalyzed cycloadditions.
Co-reporter:Renhe Liu, Min Zhang, Gabrielle Winston-McPherson and Weiping Tang
Chemical Communications 2013 - vol. 49(Issue 39) pp:NaN4378-4378
Publication Date(Web):2012/07/24
DOI:10.1039/C2CC34609E
Regioselective ring expansion of alkynyl cyclopropanes to highly substituted cyclobutenes was developed. The reaction involves a copper-catalyzed cycloaddition of an alkyne with an arylsulfonyl azide and a silver-catalyzed carbene formation followed by ring expansion of a cyclopropyl carbene intermediate.
Co-reporter:Casi M. Schienebeck, Patrick J. Robichaux, Xiaoxun Li, Lianqing Chen and Weiping Tang
Chemical Communications 2013 - vol. 49(Issue 26) pp:NaN2618-2618
Publication Date(Web):2013/02/11
DOI:10.1039/C3CC40634B
We systematically examined the effect of different esters on the rhodium-catalyzed intermolecular [5+2] cycloaddition of 3-acyloxy-1,4-enynes and alkynes with a concomitant 1,2-acyloxy migration. Significant rate acceleration was observed for benzoate substrates bearing an electron-donating substituent. The cycloaddition can now be conducted under much more practical conditions for most terminal alkynes.
Histone deacetylase 6
(2S,3R)-3,4-Dihydro-3-isopropyl-2-phenyl-2H-pyrimido[2,1-b]benzothiazole
4,7,9-trihydroxy-1-(4-hydroxyphenyl)-6H-anthra[1,9-bc]furan-6-one
Propanoic acid, 2,2-dimethyl-, 1-phenyl-2-propyn-1-yl ester
Cyclohexanecarboxaldehyde, 1-(2-propynyl)-