title: Understanding α,β-unsaturated imine formation from amine additions to α,β-unsaturated aldehydes and ketones: an analytical and theoretical investigation.
abstract: A combination of in situ IR spectroscopy (ReactIR) and DFT calculations have been used to understand what factors govern the selectivity in the addition of primary amines to α,β-unsaturated aldehydes and ketones, i.e., 1,2- versus 1,4-addition. It has been found that the 1,2-addition products (α,β-unsaturated imines following addition and elimination) usually predominate for most systems. However, exceptions, such as methyl vinyl ketone, selectively give 1,4-addition products. This has been rationalized by DFT calculations that show that major conformational effects are involved, controlled mainly by steric effects of carbonyl substituents, resulting in a model that provides simple and predictable preparation of α,β-unsaturated imines for in situ utilization in synthesis.
authors.affiliation: Centre for Sustainable Chemical Processes, Department of Chemistry, Science Laboratories, Durham University , South Road, Durham DH1 3LE, U.K.
authors.forename: Adam D J
authors.initials: AD
authors.lastname: Calow
authors.forename: Jorge J
authors.initials: JJ
authors.lastname: Carbó
authors.forename: Jessica
authors.initials: J
authors.lastname: Cid
authors.forename: Elena
authors.initials: E
authors.lastname: Fernández
authors.forename: Andrew
authors.initials: A
authors.lastname: Whiting