Catalytic Asymmetric Synthesis of Zinc Metallacycles
作者:Hayden D. Bishop、Qiang Zhao、Christopher Uyeda
DOI:10.1021/jacs.3c05885
日期:2023.9.20
Transition-metal-catalyzed reductive coupling reactions of alkynes and imines are attractive methods for the synthesis of chiral allylic amines. Mechanistically, these reactions involve oxidative cyclization of the alkyne and the imine to generate a metallacyclic intermediate, which then reacts with H2 or a H2 surrogate to form the product. As an alternative to this hydrogenolysis pathway, here we
A new preparation of cis-N-sulfonylaziridines from N-sulfonylaldimines using trimethylsilyldiazomethane
作者:Rina Hori、Toyohiko Aoyama、Takayuki Shioiri*
DOI:10.1016/s0040-4039(00)01601-4
日期:2000.12
Trimethylsilyldiazomethane smoothly reacts with N-sulfonylaldimines to give 2-substituted N-sulfonyl-3-trimethylsilylaziridines in good yields with high cis selectivity.
Asymmetric Activation oftropos 2,2′-Biphenol with Cinchonine Generates an Effective Catalyst for the Asymmetric Strecker Reaction ofN-Tosyl-Protected Aldimines and Ketoimines
作者:Lorenzo Zani、Silvia Alesi、Pier Giorgio Cozzi、Carsten Bolm
DOI:10.1021/jo052273o
日期:2006.2.1
[GRAPHICS]The treatment of various aromatic and aliphatic aldimines with a mixture of a terminal alkyne and a commercially available dimethylzinc solution in toluene yields the corresponding protected propargylic amines in moderate to excellent yields. The reaction proceeds in the absence of any activator. These observations led to the development of a three-component synthesis of propargylic amines in which the product was obtained upon mixing an aldehyde with ortho-methoxyaniline and phenylacetylene in the presence of dimethylzinc, through in situ formation of the corresponding imine.
Cycloaddition of Lithium Ynolate to Imines: Synthesis of 3,4-Disubstituted b-Lactams
Cycloaddition reaction of a lithium ynolate to N-sulfonylimines afforded 3,4-disubstituted beta-lactams. The cis-products were synthesized in high diastereoselectivity via quenching of the intermediate, beta-lactam enolates, with phenol.