A new type of cyclic amino-functionalized s-cis boroxyvinylcarbene complex of group 6 metals has been synthesized. These complexes underwent Diels−Alder-type reactions with 2-amino 1,3-dienes that proceeded with complete regioselectivity and high exo or endo diastereoselectivity, which was found to be highly dependent on the nature of the substituents on the diene. When chiral 2-amino-5-alkoxy dienes
Catalytic aminomercuration of 3-alken-1-ynes leads to 1-aza-1,3-butadienes and 2-amino-1,3-butadienes. Under appropriate reaction conditions it is possible to prepare these compounds via mercuration of 3-alken-1-ynes in the presence of either aromatic or aliphatic primary and secondary amines. Depending on the substituents in the starting 3-alken-1-yne, the mercuration reaction may afford gamma-amino enamines instead of 2-amino-1,3-butadienes and 3-imino amines or 4-amino-1-aza-1,3-butadienes instead of 1-aza-1,3-butadienes.
Solid-Phase Synthesis of Polysubstituted Piperidines by Imino-Diels−Alder Cycloaddition of 2-Amino-1,3-butadienes with Solid-Supported Imines
[GRAPHICS]The solid-phase imino-Diels-Alder reaction of 2-amino-1,3-butadienes with solid-supported imines is described. The reaction furnishes 4-piperidones and 4-aminopiperidines with high diastereoselectivity and with very good yields and purity after the release from the solid support. The possibility of introducing variations in both cycloaddition partners gives rise to substituted piperidines with up to five elements of diversity.
Asymmetric Exo-Selective Diels-Alder Reactions of Cyclic BF2 Adducts of Functionalized Fischer Vinylcarbene Complexes with Chiral 2-Amino-1,3-dienes
Stereoselective Synthesis of Seven-Membered Carbocycles from 2-Amino-1,3-butadienes and Vinyl Chromium Fischer-Type Carbenes
作者:Jose Barluenga、Fernando Aznar、Alfredo Martin、Jesus T. Vazquez
DOI:10.1021/ja00142a006
日期:1995.9
Seven-membered ring carbocycles are prepared by reaction of easily avaliable 2-amino-1,3-butadienes with vinyl Fischer carbenes. Hydrolysis of the cycloadduct initially formed gives rise to cyclohepta-1,3-diones with total regio- and stereoselectivity in a one-pot process. When 2-aminobutadienes bearing a prolinol derivative as a chiral auxiliary are used, the corresponding cyclic diketones are obtained with very high enantiomeric excesses. The absolute configuration of the stereogenic centers generated was determined with the aid of ROESY and CD measurements.