Synthesis of novel electron-deficient chromone-fused dienes via phosphine catalyzed [4+2] annulation
摘要:
alpha-Chromonyl ketoesters undergo phosphine catalyzed [4+2]-annulation reactions with acetylene carboxylates to yield tricyclic benzopyrones in good yields. Under mild acidic conditions, the tricyclic benzopyrones rearrange to provide highly substituted and electron-poor chromone-fused dienes in good yields. (C) 2011 Elsevier Ltd. All rights reserved.
Application of E1cB Elimination in Asymmetric Organocatalytic Cascade Reactions To Construct Polyheterocyclic Compounds
作者:Zhi-Hao You、Ying-Han Chen、Yu Tang、Yan-Kai Liu
DOI:10.1021/acs.orglett.9b03138
日期:2019.10.18
By introducing a carbon functionality at 2-position of chromane, the formal asymmetric functionalization of the 3-position of 2-substituted chromane has been realized via a highly chemo-, regio-, and stereoselective organocatalyticcascadereaction in a sequential one-pot manner involving an E1cB mechanism governed ring-opening process. Critical to our success was the design of a chiral dipeptide-based
alpha-Chromonyl ketoesters undergo phosphine catalyzed [4+2]-annulation reactions with acetylene carboxylates to yield tricyclic benzopyrones in good yields. Under mild acidic conditions, the tricyclic benzopyrones rearrange to provide highly substituted and electron-poor chromone-fused dienes in good yields. (C) 2011 Elsevier Ltd. All rights reserved.