Efficient Synthesis of Maleimides and Carbazoles via Zn(OTf)2-Catalyzed Tandem Annulations of Isonitriles and Allenic Esters
摘要:
Lewis acid Zn(OTf)(2)-catalyzed tandem annulations of isonitriles and allenic esters which lead to efficient and flexible syntheses of a range of biologically significant maleimides and carbazoles and related compounds are reported. A mechanistic rationale is proposed to account for the observed reactivity.
Efficient Synthesis of Maleimides and Carbazoles via Zn(OTf)2-Catalyzed Tandem Annulations of Isonitriles and Allenic Esters
摘要:
Lewis acid Zn(OTf)(2)-catalyzed tandem annulations of isonitriles and allenic esters which lead to efficient and flexible syntheses of a range of biologically significant maleimides and carbazoles and related compounds are reported. A mechanistic rationale is proposed to account for the observed reactivity.
A Straightforward Synthesis of Cyclobutenones via a Tandem Michael Addition/Cyclization Reaction of 2,3-Allenoates with Organozincs
作者:Guobi Chai、Shangze Wu、Chunling Fu、Shengming Ma
DOI:10.1021/ja1108694
日期:2011.3.23
polysubstituted cyclobutenones, which are not readily available from traditional methods due to the intrinsic ring strain, is described. The reaction of 2,3-allenoates and organozinc reagents proceeds via a tandem Michael addition/cyclic 1,2-addition/elimination mechanism with the functional groups from the organozinc reagents being introduced to the 3-position of the cyclobutenone products regiospecifically