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
Enantioselective Synthesis of 3,5,6‐Substituted Dihydropyranones and Dihydropyridinones using Isothiourea‐Mediated Catalysis
作者:Daniel G. Stark、Louis C. Morrill、David B. Cordes、Alexandra M. Z. Slawin、Timothy J. C. O'Riordan、Andrew D. Smith
DOI:10.1002/asia.201500907
日期:2016.2
isothiourea-catalyzed processes has been expanded and explored through the use of 2-N-tosyliminoacrylates and 2-aroylacrylates in a Michael addition-lactonization/lactamization cascade reaction. Notably, to ensure reproducibility it is essential to use homoanhydrides as ammonium enolate precursors with 2-aroyl acrylates, while carboxylic acids can be used with 2-N-tosyliminoacrylates, delivering a range of 3,5,6-substituted
Diastereodivergent synthesis of cyclopropanes <i>via</i> on-water [2 + 1] annulations of diazo compounds with electron-deficient alkenes
作者:Qing-Zhu Li、Xiang Zhang、Ke Xie、Qing-Song Dai、Rong Zeng、Yan-Qing Liu、Zhi-Qiang Jia、Xin Feng、Jun-Long Li
DOI:10.1039/c9gc00278b
日期:——
cyclopropanation of diazo compounds and electron-deficient alkenes under metal- and catalyst-freeconditions was developed. The use of water as the sole solvent dramatically increased the efficiency of the reaction. This on-water synthesis approach featured numerous advantages, including high yield, broad substrate scope and environmentally friendly conditions. Moreover, a simple substrate-engineering strategy was