A mild and reproducible method for the formation of a nonstabilized azomethine ylide was developed by photoinduced reaction catalyzed with eosin Y under green light irradiation. Resulting 1,3-dipole was trapped with fluoroalkenes, fluoroalkylated alkenes, and representative dipolarophiles to access pyrrolidine scaffolds, including spirocyclic compounds. The mechanism involved in this transformation
Direct synthesis of N-substituted 1,3-oxazolidines via a hetero-domino Petasis borono-Mannich reaction of 1,2-amino alcohols, formaldehyde, and organoboronic acids
作者:Yiting Zheng、Lu Sun、Jiayi Wang、Gonghua Song
DOI:10.1007/s10593-019-02511-8
日期:2019.7
A simple and convenient approach to the synthesis of N-substituted 1,3-oxazolidines via a hetero-domino Petasisborono-Mannichreaction of 1,2-amino alcohols, formaldehyde, and organoboronic acids has been reported. The transformation provides an effective and complementary pathway toward 1,3-oxazolidine derivatives.
Electrochemical Generation of a Nonstabilized Azomethine Ylide: Access to Substituted <i>N</i>-Heterocycles
作者:Rakesh Kumar、Prabal Banerjee
DOI:10.1021/acs.joc.1c02069
日期:2021.11.19
Azomethineylides are fascinating 1,3-dipoles for [3 + 2] cycloadditionreactions toward the construction of N-heterocycles. Herein, an efficient and environmentally benign electrochemical approach for the generation of a nonstabilized azomethineylide has been established under metal-free and external oxidant-free conditions. The resulting 1,3-dipole undergoes a [3 + 2] cycloadditionreaction with
Synthesis of 5-Aryloxazolidines via 1,3-Dipolar Cycloaddition Reaction of a Non-Stabilized Azomethine Ylide with Aromatic Aldehydes
作者:John H. Ryan、Nadia Spiccia、Leon S.-M. Wong、Andrew B. Holmes
DOI:10.1071/ch07282
日期:——
The 1,3-dipolarcycloadditionreaction of a non-stabilized azomethine ylide 4a, formed in situ from N-(methoxymethyl)-N-(trimethylsilylmethyl)benzylamine 5 and a catalytic amount of trifluoroacetic acid, with aromatic aldehydes 3 gives rise to N-benzyl-5-aryloxazolidines 1. Under these conditions, 4-hydroxybenzaldehyde 3p undergoes two-fold addition of azomethine ylide 4a to afford bis adduct 11.
3-dipolar cycloaddition of chiral azomethine ylides with several dipolarophiles has been studied. Reasonable levels of such diastereoselectivity have been found when optically active α-cyanoaminosilanes are employed as azomethine ylide equivalents. These compounds can be prepared in multigram quantities by treating the appropriate chiral amine with chlorotrimethylsilane followed by reaction of the resulting