The first highly enantioselective allylic–allylic alkylation of α,α‐dicyanoalkenes and Morita–Baylis–Hillman carbonates by dualcatalysis of (DHQD)2AQN and (S)‐BINOL has been investigated. Excellent stereoselectivities have been achieved for a broad spectrum of substrates (d.r. > 99:1, up to 99 % ee). The multifunctional allylic products could be efficiently converted to a range of complex chiral cyclic
Cu(OTf)2/Et3N-promoted cyclocondensation of activated α-methylene alkenes and nitroolefins: a novel one-pot synthesis of polysubstituted benzenes
作者:Weike Su、Kai Ding、Zhiwei Chen
DOI:10.1016/j.tetlet.2008.11.081
日期:2009.2
A simple and efficient one-potsynthesis of polyfunctionalized benzenes has been developed via cyclocondensation of activated α-methylene alkenes such as vinyl malononitriles and ethyl vinyl cyanoacetates with nitroolefins using Cu(OTf)2/Et3N as a novel catalytic system.
通过使用Cu(OTf)2 / Et 3 N作为新型催化体系,将活化的α-亚甲基烯烃(如乙烯基丙二腈和乙基乙烯基氰基乙酸酯)与硝基烯烃进行环缩反应,已开发出一种简单高效的一锅多官能苯合成方法。
Construction of Chiral Multi-Functionalized Polyheterocyclic Benzopyran Derivatives by Using an Asymmetric Organocatalytic Domino Reaction
The asymmetricdominoreaction of various α,α-dicyano olefins to 3-nitro-2H-chromenes was studied employing readily available cinchona-derived bifunctional thioureas as organocatalysts. These new transformations were highly regio-, chemo-, diastereo-, and enantioselective simultaneously giving chiralmulti-functionalizedpolyheterocyclicbenzopyranderivatives with multi-chiral carbon centers.
been devised to furnish densely functionalized 3‐hydroxyindanone scaffolds in high yields with excellent diastereoselectivity. Unlike preceding approaches that account for the formation of the pentanoid ring, this strategy features construction of the aromatic ring. The protocol is scalable, displays very broad substrates scope including late‐stage functionalization of bioactive estrone, applicable
afford 2,3-dihydroisoxazoles (2,3-dihydroisoxazoles can be easily isolated by filtration) in excellent yields under mild and environmentally benign conditions. A one-pot reaction in tandem with an unexpected ring-opening of 2,3-dihydroisoxazoles has been developed as well.