Thioacids and thioacid salts for determining the enantiomeric excess of chiral compounds containing an electrophilic carbon center
申请人:Richman Jack E.
公开号:US20090181462A1
公开(公告)日:2009-07-16
The invention provides novel chiral compounds including 2-methoxy-2-trifluoromethylphenylacetic thioacid useful to react with and analyze other chiral compounds that have an electrophilic chiral carbon center.
A general asymmetric copper-catalysed Sonogashira C(sp3)–C(sp) coupling
作者:Xiao-Yang Dong、Yu-Feng Zhang、Can-Liang Ma、Qiang-Shuai Gu、Fu-Li Wang、Zhong-Liang Li、Sheng-Peng Jiang、Xin-Yuan Liu
DOI:10.1038/s41557-019-0346-2
日期:2019.12
versatile reaction for the straightforward formation of C–C bonds, forging the carbon skeletons of broadly useful functionalized molecules. However, asymmetric Sonogashira coupling, particularly for C(sp3)–C(sp) bond formation, has remained largely unexplored. Here we demonstrate a general stereoconvergent Sonogashira C(sp3)–C(sp) cross-coupling of a broad range of terminal alkynes and racemic alkyl halides
Salts of Mosher’s thioacid: agents for determining the enantiomer excess of SN2 substrates
作者:Jack E. Richman
DOI:10.1016/j.tetlet.2010.03.041
日期:2010.5
salts with Proton Sponge [1,8-bis(dimethylamino)naphthalene]. These salts are powerful nucleophiles that react cleanly (SN2 inversion) in CDCl3 with optically active alkylhalides ranging in reactivities from unactivated alkyl bromides and iodides to benzylic bromides. The diastereomeric excess (de) of the thioester products indicates the enantiomeric excess (ee) of the starting alkylhalides.
作者:Sergiy V. Chepyshev、Bhaskar Reddy Pitta、Saidi Reddy Vangala、J. Armando Lujan‐Montelongo、Omar W. Steward、Fraser F. Fleming
DOI:10.1002/chem.201705791
日期:2018.2.26
Diastereoselective alkylation of prochiral oxonitrile dianions with secondary alkyl halides efficiently installs two contiguous stereogenic centers. The confluence of nucleophilic trajectory and the electrophile chirality causes distinct steric differences that allow efficient discrimination for one of the six possible conformers. Numerous oxonitrile‐derived dianions efficiently displace secondary
One-Pot Synthesis of 3-Substituted 3,4-Dihydro-1,2,3-benzotriazine Derivatives Based on the Reaction of<i>o</i>-Bromobenzyl Azides with Butyllithium
作者:Kazuhiro Kobayashi、Yuuki Chikazawa
DOI:10.1002/hlca.201500234
日期:2016.1
An efficient one‐pot procedure for the preparation of 3‐substituted 3,4‐dihydro‐1,2,3‐benzotriazines 2, 3, and 4from o‐bromobenzyl azides 1 is described. The reaction of these azides with BuLi in THF at −78° generates o‐lithiobenzyl azides via the Br/Li exchange. These lithium compounds immediately undergo intramolecular cyclization to give the corresponding (dihydro‐1,2,3‐benzotriazinyl)lithium intermediates