1,2-Nucleophilic addition of 2-(picolyl)organoboranes to nitrile, aldehyde, ketone, and amide.
A series of 2-(picolyl)borane molecules were synthesized as products of the reaction between 2-(picolyl)lithium and R(2)BOMe (R = ethyl, 9-BBN, phenyl, 9-borafluorenyl). The 2-(picolyl)boranes were dimeric; whereas, monomers coordinated to LiOMe could be isolated when the synthesis was carried out in the presence of TMEDA and THF. The 2-(picolyl)boranes undergo reaction with nitriles, ketones, aldehydes, and amides with apparent 1,2-addition of the B-C(picolyl) bond to the unsaturated bond. Theoretical models reveal the presence of a donor orbital on the 2-(picolyl)borane with significant electron density at the benzylic carbon that we conclude was involved in nucleophilic attack on the electrophilic center of unsaturated organic functional groups.
Department of Chemistry, University of South Dakota, Vermillion, 57069, USA.
Jung-Ho
JH
Son
James D
JD
Hoefelmeyer
D000447:Aldehydes / Q000737:chemistry*; D000577:Amides / Q000737:chemistry*; D001880:Boranes / Q000737:chemistry*; D004583:Electrons; D007659:Ketones / Q000737:chemistry*; D008958:Models, Molecular; D009570:Nitriles / Q000737:chemistry*; D010848:Picolinic Acids / Q000737:chemistry*
D000447:Aldehydes; D000577:Amides; D001880:Boranes; D007659:Ketones; D009570:Nitriles; D010848:Picolinic Acids