Stoichiometric reductions of alkyl-substituted ketones and aldehydes to borinic esters

Lauren E Longobardi; Connie Tang; Douglas W Stephan

doi:10.1039/c4dt02648a

Stoichiometric reductions of alkyl-substituted ketones and aldehydes to borinic esters

Dalton Trans. 2014 Nov 14;43(42):15723-6. doi: 10.1039/c4dt02648a.

Authors

Lauren E Longobardi¹, Connie Tang, Douglas W Stephan

Affiliation

¹ Department of Chemistry, 80 St George St, University of Toronto, Toronto, Ontario, Canada M5S3H6. dstephan@chem.utoronto.ca.

PMID: 25250629
DOI: 10.1039/c4dt02648a

Abstract

A series of alkyl-substituted ketones are shown to activate hydrogen in the presence of B(C6F5)3, affording the corresponding borinic esters RR'CHOB(C6F5)2. The mechanism is shown to proceed via H2 activation, hydride delivery and protonation of a C6F5 group. The aliphatic aldehyde Et2CHCHO reacts with B(C6F5)3 or BPh3 to give boron enolates Et2C[double bond, length as m-dash]CH(OBAr2) (Ar = C6F5, Ph). These latter species are amenable to FLP-catalyzed reduction to the corresponding borinic esters.