Catalyst-Free Formal Conjugate Addition/Aldol or Mannich Multicomponent Reactions of Mixed Aliphatic Organozinc Reagents, π-Electrophiles and Michael Acceptors
作者:Marine Pinaud、Marc Presset、Erwan Le Gall
DOI:10.3390/molecules28031401
日期:——
reagents with Michaelacceptors and aldehydes, ketones or activated imines are described. Primary, secondary and tertiary alkylzinc reagents, pre-generated in acetonitrile from the corresponding iodoalkanes, were used in the process, leading to the very efficient formation of a variety of β-hydroxycarbonyl compounds. The imines showed more contrasting results, due to the direct addition of the organozinc
描述了混合烷基锌试剂与迈克尔受体和醛、酮或活化亚胺的无催化剂多组分反应。该过程中使用了由相应的碘烷烃在乙腈中预先生成的伯、仲和叔烷基锌试剂,从而非常有效地形成各种β-羟基羰基化合物。由于有机锌化合物直接加成到 C=N 键上,亚胺显示出更具对比性的结果。涉及 TEMPO 的机理分析解释了反应的极性而不是自由基特征。
Sequential Generation and Utilization of Radical and Anionic Species with a Novel Manganese−Lead Reducing Agent. Three-Component Coupling Reactions of Alkyl Iodides, Electron-Deficient Olefins, and Carbonyl Compounds
Successive Carbon–Carbon Bond Formation by Sequential Generation of Radical and Anionic Species with Manganese and Catalytic Amounts of PbCl<sub>2</sub>and Me<sub>3</sub>SiCl
moderate reducing system derived from manganesemetal and a catalyticamount of PbCl2 and Me3SiCl. Although the role of PbCl2 is unclear, addition of a catalyticamount of the salt is essential for reducing the iodoalkane. The reaction proceeds with primary, secondary, and tertiary iodoalkanes. Both acrylonitrile and acrylic esters can be employed as activated olefins, while the reaction with an alkyl