Thermal and hyperbaric addition ofN,N- andN,O- binucleophiles on cycloalkylidenic bromo esters
作者:Alexandre Y. Rulev、Jacques Maddaluno
DOI:10.1002/poc.493
日期:2002.8
and N,O- and N,N-binucleophiles (such as ethylenediamines or aminoethanols) provides morpholin-2-ones and piperazin-2-ones. Thus, in contrast to simple primary amines, binucleophiles do not form spirocyclic derivatives. The expected Michael addition competes with a cascade reaction consisting of a migration of the double bond followed by the substitution of the newly established allylic halogen and a
The reaction between primary amines and 2-bromo-2-(cycloalkylidene)acetates in alcohol under high pressure provides the expected spiroaziridines in good yields and diastereomeric excesses. With bulky or aromatic amines, this reaction competes with the migration of the double bond, which, migrating from an exo to an endocyclic position, provides an intermediate allylic α-bromo ester, immediately converted