Mechanistic insights into the catalytic asymmetric allylboration of ketones: Brønsted or Lewis acid activation?
Binaphthol ligands promote the enantioselective addition of allylboronates to ketones. In this study, we use DFT calculations to establish the identity of the reacting chiral species. Our results show that a cyclic Lewis acid-activated boronate is the most reactive species on the basis of calculated energy barriers, and it is only this species that leads to the correct enantiomer. The stereoinduction can be rationalized in terms of the competing chairlike transition structures.
Paton
Robert S
RS
Unilever Centre for Molecular Science Informatics, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
Goodman
Jonathan M
JM
Pellegrinet
Silvina C
SC
D000498:Allyl Compounds / Q000737:chemistry*; D001880:Boranes / Q000138:chemical synthesis* / Q000737:chemistry; D001897:Boronic Acids / Q000737:chemistry*; D002384:Catalysis; D007659:Ketones / Q000737:chemistry*; D008024:Ligands; D008956:Models, Chemical; D015394:Molecular Structure; D009284:Naphthols / Q000737:chemistry*; D013237:Stereoisomerism
D000498:Allyl Compounds; D001880:Boranes; D001897:Boronic Acids; D007659:Ketones; D008024:Ligands; D009284:Naphthols