Et3B-mediated radical-polar crossover reaction for single-step coupling of O,Te-acetal, α,β-unsaturated ketones, and aldehydes/ketones.
Et3B-mediated three-component coupling reactions between O,Te-acetal, α,β-unsaturated ketones, and aldehydes/ketones were developed. Et3B promoted the generation of the potently reactive bridgehead radical from the O,Te-acetal of the trioxaadamantane structure and converted the α-carbonyl radical of the resultant two-component adduct to the boron enolate, which then underwent a stereoselective aldol reaction with the aldehyde/ketone. This powerful, yet mild, radical-polar crossover reaction efficiently connected the hindered linkages between the three units and selectively introduced three new stereocenters.
Graduate School of Pharmaceutical Sciences, The University of Tokyo , Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Daigo
D
Kamimura
Daisuke
D
Urabe
Masanori
M
Nagatomo
Masayuki
M
Inoue
D000080:Acetals; D000447:Aldehydes / Q000737:chemistry*; D001880:Boranes / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism; D013691:Tellurium / Q000737:chemistry*
D000080:Acetals; D000447:Aldehydes; D001880:Boranes; D007659:Ketones; D013691:Tellurium; C079756:triethylborane