An asymmetric organocatalytic addition of fluorinated phenylsulfonylnitromethane to isatin-derived ketimines was developed. The reaction was efficiently catalyzed by chiral tertiary amine, cinchonine. This methodology provides a new type of optically active compounds with two adjacent quaternary carbon stereocenters in good yields (up to 96%), moderated diastereoselectivity (up to 5.7:1 dr) and excellent
Phenylalanine-based bifunctionalthiourea derivatives promoted the asymmetricMichaeladdition of α-fluoro-α-phenylsulfonyl ketones to nitroolefins, affording enantiomerically enriched fluorine-containing multifunctional molecules containing adjoining chiral fluorine-substituted quaternary and tertiary centers in good yields and enantioselectivities.
Divergent Regio‐ and Stereoselective Gold‐catalyzed Synthesis of α‐Fluorosulfones and β‐Fluorovinylsulfones from Alkynylsulfones
作者:Xiaojun Zeng、Shiwen Liu、Gerald B. Hammond、Bo Xu
DOI:10.1002/chem.201703179
日期:2017.9.4
We developed a widely applicable, highly efficient synthesis of α‐fluorosulfone and β‐fluorovinylsulfone catalyzed by gold. Starting with alkynyl sulfone 1, an [Au]/HF/N‐oxide system gives α‐fluorosulfone 3 via a gold carbene intermediate, and, if no N‐oxide is used, direct addition of HF to 1 gives vinyl sulfone 4 via a vinylfluoro gold intermediate. Both methods have good functional group tolerance
Enantioselective Synthesis of α-Fluorinated β-Amino Acid Derivatives by an Asymmetric Mannich Reaction and Selective Deacylation/Decarboxylation Reactions
作者:Yuanhang Pan、Yujun Zhao、Ting Ma、Yuanyong Yang、Hongjun Liu、Zhiyong Jiang、Choon-Hong Tan
DOI:10.1002/chem.200902830
日期:2010.1.18
degradation: A highly enantio‐ and diastereoselective guanidine‐catalyzed Mannich reaction was developed with α‐fluoro‐β‐keto acyloxazolidinone as the fluorocarbon nucleophile (see scheme). α‐Fluoro‐β‐amino ester and α‐fluoro‐β‐amino ketones with chiral fluorinated carbon were obtained by selective deacylation and decarboxylation reactions, respectively.