Asymmetric Michael Addition of Ketones to Alkylidene Malonates and Allylidene Malonates via Enamine–Metal Lewis Acid Bifunctional Catalysis
作者:Lu Liu、Ryan Sarkisian、Zhenghu Xu、Hong Wang
DOI:10.1021/jo301070s
日期:2012.9.7
Novel enamine–metal Lewis acid bifunctional catalysts were successfully applied to the asymmetric Michaeladdition of ketones to alkylidenemalonates, offering excellent stereoselectivity (up to >99% ee and >99:1 dr). The asymmetric Michaeladdition of ketones to allylidene malonates was also achieved.
Highly Enantioselective Michael Addition of Ketone to Alkylidene Malonates Catalyzed by Binaphthyl Sulfonimides in Water
作者:Shengjian Jia、Chunhua Luo、Daming Du
DOI:10.1002/cjoc.201200910
日期:2012.11
Binaphthyl sulfonimides have been developed to catalyze the asymmetric Michaeladdition of ketone to alkylidene malonates, affording the corresponding Michael products in good to high yields (up to 98%) with good to excellent diastereoselectivity (up to 99:1 dr) and enantioselectivity (up to 92% ee) under mild conditions using environmentally benign water as the solvent.
study, stereoselective conjugate addition of ketones to alkylidenemalonates using organocatalyst has been developed. The reaction in the presence of 20 mol% of a novel thiourea‐sulfonamide organocatalyst afforded conjugate adducts in moderate to high yields (up to 81%) under mild reaction conditions. Excellent diastereoselectivity (up to 98:2 dr) and enantioselectivity (up to 88% ee) were achieved.
Enantioselective Organocatalytic Michael Addition of Ketones to Alkylidene Malonates
作者:Siang-En Syu、Chan-Hui Huang、Ko-Wei Chen、Chia-Jui Lee、Utpal Das、Yeong-Jiunn Jang、Wenwei Lin
DOI:10.1002/chir.22055
日期:2012.8
studied for the direct asymmetric Michaeladdition of ketones and alkylidenemalonates. The organocatalyst (S)‐2‐((naphthalen‐2‐ylthio)methyl)pyrrolidine, bearing a pyrrolidine and a sulfide moiety, showed a very high catalytic activity in the absence of additives. The reaction condition is mild, and the Michael adducts were obtained in very good enantioselectivities (up to 96%), diastereoselectivities