Manganese η2-complexes as auxiliaries for stereoselective aldol synthesis of allenyl carbinols

Manishabrata Bhowmick; Salvatore D Lepore

doi:10.1021/ol1021096

Manganese η2-complexes as auxiliaries for stereoselective aldol synthesis of allenyl carbinols

Org Lett. 2010 Nov 5;12(21):5078-80. doi: 10.1021/ol1021096.

Authors

Manishabrata Bhowmick¹, Salvatore D Lepore

Affiliation

¹ Department of Chemistry, Florida Atlantic University, Boca Raton, Florida 33431, United States.

PMID: 20936852
DOI: 10.1021/ol1021096

Abstract

A convenient and robust manganese auxiliary was linked via an η(2)-bond to alkynyl esters and ketones using a mild complexation reaction with methylcyclopentadienyl manganese tricarbonyl. This complex readily underwent aldol reactions with exclusive α-substitution and in good diastereoselectivities especially with aryl ketone substrates. This selectivity has been rationalized using a cyclic transition state model in which the manganese auxiliary plays a critical role in promoting E(O)-geometry of the cumulenolate intermediate.

Publication types

Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Aldehydes / chemistry*
Alkadienes / chemistry*
Crystallography, X-Ray
Manganese / chemistry*
Methanol / chemical synthesis*
Models, Molecular
Molecular Structure
Oxidation-Reduction
Stereoisomerism

Substances

Aldehydes
Alkadienes
Manganese
propadiene
3-hydroxybutanal
Methanol

Grants and funding

NIGMS 073621-01/PHS HHS/United States