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
Organic Iron for the PdCl2/FeCl3-Cocatalyzed Coupling Cyclization of 2,3-Allenoates in the Presence of Allylic Bromides
作者:Bo Chen、Shengming Ma
DOI:10.1002/chem.201002553
日期:2011.1.17
Newcoupling: The interaction of ferric chloride with 2,3‐allenoates generates a 2‐(5H)‐furanonyl iron species, which was observed to readily undergo transmetalation with PdCl2 to result in coupling with allylic bromides (see scheme). Based on this reaction, an efficient method for the synthesis of β‐allyl polysubstituted butenolides from the easily available allylic bromides and 2,3‐allenoates has
Allenic Esters from Cyclopropenones by Lewis Base Catalysis: Substrate Scope, the Asymmetric Variant from the Dynamic Kinetic Asymmetric Transformation, and Mechanistic Studies
作者:Yin Wei、Wen-Tao Zhao、Yuan-Liang Yang、Zhen Zhang、Min Shi
DOI:10.1002/cctc.201500466
日期:2015.10
corresponding asymmetric reaction in the presence of multifunctional chiral phosphine catalyst. The reaction mechanism was disclosed by using NMR tracing experiments, MS, and DFT calculations. Notably, the asymmetric reaction was proved to be a dynamickineticasymmetrictransformationbased on the control experiments, and the detailed mechanism of this transformation revealed by theoretical investigations
Efficient Synthesis of Maleimides and Carbazoles via Zn(OTf)<sub>2</sub>-Catalyzed Tandem Annulations of Isonitriles and Allenic Esters
作者:Yuanzhen Li、Haixia Zou、Jianxian Gong、Jing Xiang、Tuoping Luo、Junmin Quan、Guoxin Wang、Zhen Yang
DOI:10.1021/ol7018086
日期:2007.9.1
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.
Lewis base-catalyzed reactions of cyclopropenones: novel synthesis of mono- or multi-substituted allenic esters
作者:Yuan-Liang Yang、Zhen Zhang、Xiao-Nan Zhang、De Wang、Yin Wei、Min Shi
DOI:10.1039/c3cc46470a
日期:——
The reactions of cyclopropenones with nucleophiles (H2O or methanol) could be catalyzed by nitrogen-containing Lewis bases or phosphorus-containing Lewis bases, affording the corresponding mono- or multi-substituted allenic esters in moderate to excellent yields.