Pyrrolidine and Piperidine Formation via Copper(II) Carboxylate-Promoted Intramolecular Carboamination of Unactivated Olefins: Diastereoselectivity and Mechanism
An expanded substrate scope and in-depth analysis of the reaction mechanism of the copper(II) carboxylate-promoted intramolecular carboamination of unactivated alkenes is described. This method provides access to N-functionalized pyrrolidines and piperidines. Both aromatic and aliphatic γ- and δ-alk...
Saved in:
Published in | Journal of organic chemistry Vol. 72; no. 10; pp. 3896 - 3905 |
---|---|
Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
WASHINGTON
American Chemical Society
11.05.2007
Amer Chemical Soc |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | An expanded substrate scope and in-depth analysis of the reaction mechanism of the copper(II) carboxylate-promoted intramolecular carboamination of unactivated alkenes is described. This method provides access to N-functionalized pyrrolidines and piperidines. Both aromatic and aliphatic γ- and δ-alkenyl N-arylsulfonamides undergo the oxidative cyclization reaction efficiently. N-Benzoyl-2-allylaniline also underwent the oxidative cyclization. The terminal olefin substrates examined were more reactive than those with internal olefins, and the latter terminated in elimination rather than carbon−carbon bond formation. The efficiency of the reaction was enhanced by the use of more organic soluble copper(II) carboxylate salts, copper(II) neodecanoate in particular. The reaction times were reduced by the use of microwave heating. High levels of diastereoselectivity were observed in the synthesis of 2,5-disubstituted pyrrolidines, wherein the cis substitution pattern predominates. The mechanism of the reaction is discussed in the context of the observed reactivity and in comparison to analogous reactions promoted by other reagents and conditions. Our evidence supports a mechanism wherein the N−C bond is formed via intramolecular syn aminocupration and the C−C bond is formed via intramolecular addition of a primary carbon radical to an aromatic ring. |
---|---|
Bibliography: | istex:4C577A796A21406D0CE816F2790FF968DCA8FA54 ark:/67375/TPS-RCJKGNWK-7 Medline NIH RePORTER ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0022-3263 1520-6904 |
DOI: | 10.1021/jo070321u |