The first one‐pot tandem Michael addition/enantioselective Conia‐ene cyclization of N‐protected prop‐2‐yn‐1‐amines with 2‐methylene‐3‐oxoalkanoates promoted by chiral iron(III)/silver(I) cooperative catalysts has been developed. Alkyl 4‐methylenepyrrolidine‐3‐acyl‐3‐carboxylates, which can be transformed into β‐proline derivatives, are obtained in high yield with high enantioselectivity.
Electron-Donor–Acceptor Complex-Enabled Flow Methodology for the Hydrotrifluoromethylation of Unsaturated β-Keto Esters
作者:Gabriel M. F. Batista、Pedro P. de Castro、Hélio F. Dos Santos、Kleber T. de Oliveira、Giovanni W. Amarante
DOI:10.1021/acs.orglett.0c03187
日期:2020.11.6
(EDA) complex-enabled flow photochemical hydrotrifluoromethylation of unsaturated β-keto esters is described. The developed protocol has an easy experimental procedure and does not require the use of transition-metal-based photocatalysts, allowing the isolation of 14 new compounds in up to 86% yield. Control experiments and computational studies revealed that the reaction proceeds through a Michael-type
Diethyl phosphite mediated reductive [1 + 4] annulation of α-ketoesters with α, β-unsaturated ketones and synthesis of polysubstituted 2,3-dihydrofurans
作者:Feixue Xue、Xiangyu Chen、Zhengjie He
DOI:10.1016/j.tet.2022.132646
日期:2022.1
A diethyl phosphite mediated reductive [1 + 4] annulation of α-ketoesters with α, β-unsaturatedketones has been developed, which provides an effective and simple method to prepare polysubstituted 2,3-dihydrofurans bearing a quaternary carbon center in fair to excellent yields. In the reaction, the in situ generated [1,2]-phospha-Brook rearrangement adduct of phosphite and α-ketoester presumably serves
A serendipitous carbon-carbonbondcleavage in the reaction of benzoyl acrylates, derived from Morita-Baylis-Hillman adducts, with hydrazines delivered new N',N'-disubstituted benzohydrazides. The reaction features a regioselective formation of two carbon-nitrogen bonds and works well with a range of acrylates and hydrazines. A brief mechanistic investigation alluded to a cyclic hemiaminal as a plausible
Diamine-mediated degradative dimerisation of Morita–Baylis–Hillman ketones
作者:Ajit Kumar Jha、Anju Kumari、Srinivasan Easwar
DOI:10.1039/c9cc10068g
日期:——
A degradative dimerisation of Morita-Baylis-Hillmanketones was observed in the presence of a primary diamine. The reaction proceeded swiftly to produce methylene-bridged 1,3-dicarbonyl compounds. A brief mechanisticinvestigation alluded to a retro-Mannich reaction as the key step of the transformation.