The enantioselective organocatalysed addition of β-keto benzothiazolesulfones to N-Boc-protected imines, leading to intermediates easily transformed into optically active allylic amines or β-keto amino compounds, is presented.
Three in one: Applying an organocatalytic tandem strategy to build a library of opticallyactive alkynyl, alkenyl, and ketone products, starting from cyclic enones and β‐keto sulfones, is shown to be rapid and efficient (see scheme; R=aryl, R′=H or alkyl).
三合一:从环烯酮和β-酮砜开始,应用有机催化串联策略建立光学活性炔基,烯基和酮产物的库是快速有效的(请参阅方案; R =芳基,R '= H或烷基)。
An Unexpected Michael-Aldol-Smiles Rearrangement Sequence for the Synthesis of Versatile Optically Active Bicyclic Structures by Using Asymmetric Organocatalysis
作者:Nicole Holub、Hao Jiang、Marcio W. Paixão、Caterina Tiberi、Karl A. Jørgensen
DOI:10.1002/chem.200903274
日期:2010.4.12
A facile and simple organocatalytic procedure to generate optically active 6‐alkyl‐ and 6‐aryl‐substituted bicyclo[2.2.2]oct‐5‐en‐2‐ones is presented. The reaction is catalysed by a 9‐amino‐9‐deoxyepiquinine trifluoroacetic acid salt, which activates α,β‐unsaturated cyclic ketones for the 1,4‐addition of β‐keto benzothiazoyl sulfones in a stereoselective fashion. Subsequent intramolecular aldol reaction