Enantioselective synthesis of 4-aminopyrrolidine-2,4-dicarboxylate derivatives via Ag-catalyzed cycloaddition of azomethine ylides with alkylidene azlactones
Catalytic Enantioselective 1,3-Dipolar Cycloaddition of Azomethine Ylides with Vinyl Sulfones
作者:Tomás Llamas、Ramón Gómez Arrayás、Juan C. Carretero
DOI:10.1021/ol060314c
日期:2006.4.1
see text] A general protocol for the enantioselective catalytic 1,3-dipolarcycloaddition of azomethine ylides with aryl vinyl sulfones is described. Nearly complete exo selectivity and enantioselectivities up to 85% ee are attained with Cu(CH(3)CN)(4)ClO(4)/Taniaphos as the catalyst system. The resulting enantioenriched 3-sulfonyl cycloadducts are versatile intermediates in the synthesis of 2,5-disubstituted
[reaction: see text] Silver fluoride and cinchonaalkaloidscatalyze the diastereo- and enantioselective 1,3-dipolar cycloaddition between azomethine ylides, generated from N-alkylideneglycine esters, and acrylates to give the corresponding endo-adducts. Azomethine ylides derivedfrom aromatic and aliphatic aldehydes react in a highly diastereoselective reaction with good yields and enantioselectivities
Stereodivergency in Catalytic Asymmetric Conjugate Addition Reactions of Glycine (Ket)imines
作者:Hun Young Kim、Jian-Yuan Li、Sungkyung Kim、Kyungsoo Oh
DOI:10.1021/ja2100356
日期:2011.12.28
catalytic asymmetric conjugatereactions of glycine (ket)imines with nitroalkenes have been achieved using various chiral catalyst systems derivedfrom a multidentate amino alcohol (1). The stepwise nature of the [3 + 2] cycloaddition reactions of N-metalated azomethine ylides has also been demonstrated by highly enantio- and diastereoselective syntheses of exo-5 and endo-8 from the respective syn-4
Azomethine-isocyanide [3+2] cycloaddition to imidazoles promoted by silver and DBU
作者:Xiaoshan Huang、Xuefeng Cong、Pengbing Mi、Xihe Bi
DOI:10.1039/c7cc00772h
日期:——
A new silver-promoted [3+2] cycloaddition of azomethine ylides with isocyanides has been described to construct a variety of 1,2,4-trisubstituted imidazoles of vital bioactive molecules.