Chiral Bifunctional Phosphine Ligand Enables Gold-Catalyzed Asymmetric Isomerization and Cyclization of Propargyl Sulfonamide into Chiral 3-Pyrroline
作者:Xinpeng Cheng、Liming Zhang
DOI:10.1021/acs.orglett.1c02896
日期:2021.11.5
This work details an asymmetric gold-ligand cooperativecatalysis that transforms readily accessible chiral/achiral propargylic sulfonamides into chiral 3-pyrrolines. A bifunctional biphenyl-2-ylphosphine ligand featuring a chiral tetrahydroisoquinoline fragment is essential for the observed metal–ligand cooperation and the asymmetric induction. 2,5-cis-3-Pyrrolines are formed with excellent diastereoselectivities
Asymmetric Synthesis of α-(Diarylmethyl) Alkyl Amines through Regioselective Lithiation of α-Diarylmethanes and the Diastereoselective Addition to Ellman’s Imines
A highly regio- and diastereoselective lithiation/addition of α-diarylmethanes to N-tert-butanesulfinylimines is reported. This methodology also affords the preparation of enantiomerically pure α-(diarylmethyl) alkyl amines bearing quaternary centers.
A Flexible and Stereoselective Synthesis of Azetidin-3-ones through Gold-Catalyzed Intermolecular Oxidation of Alkynes
作者:Longwu Ye、Weimin He、Liming Zhang
DOI:10.1002/anie.201007624
日期:2011.3.28
Chiral rings made easy: Chiral azetidin‐3‐ones have been easily prepared from chiral N‐propargylsulfonamides, which in turn are readily accessible through chiral sulfinamide chemistry (see scheme). Using tert‐butylsulfonyl as the protecting group avoids unnecessary deprotection and reprotection steps, and allows its removal from the azetidine ring under acidic conditions.
Highly Stereoselective Trichloromethylation of N-(tert-Butylsulfinyl)aldimines: Facile Synthesis of Chiral α-Trichloromethylamines
作者:Ya Li、Yunlv Cao、Jiaying Gu、Wei Wang、Han Wang、Tao Zheng、Zhihua Sun
DOI:10.1002/ejoc.201001495
日期:2011.2
The first highly stereoselective and facile synthesis of α-trichloromethylamines is described by using a nucleophilic trichloromethylation strategy. With tetrabutylammonium triphenyldifluorosilicate (TBAT) as the mediator, the trichloromethyl anion (CCl 3 ― ) from TMSCCl 3 can be transferred to N-(tert-butylsulfinyl)aldimines in excellent yields and with high diastereoselectivity (≥99:1 dr).