RESUMO
An asymmetric Ni-catalyzed reductive cross-coupling of (hetero)aryl iodides and benzylic chlorides has been developed to prepare enantioenriched 1,1-diarylalkanes. As part of these studies, a new chiral bioxazoline ligand, 4-heptyl-BiOX (L1), was developed in order to obtain products in synthetically useful yield and enantioselectivity. The reaction tolerates a variety of heterocyclic coupling partners, including pyridines, pyrimidines, indoles, and piperidines.
Assuntos
Alcanos/síntese química , Níquel/química , Alcanos/química , Catálise , Hidrocarbonetos Clorados/química , Hidrocarbonetos Iodados/química , Estrutura Molecular , Oxirredução , EstereoisomerismoRESUMO
A Ni-catalyzed asymmetric reductive cross-coupling of heteroaryl iodides and α-chloronitriles has been developed. This method furnishes enantioenriched α,α-disubstituted nitriles from simple organohalide building blocks. The reaction tolerates a variety of heterocyclic coupling partners, including pyridines, pyrimidines, quinolines, thiophenes, and piperidines. The reaction proceeds under mild conditions at room temperature and precludes the need to pregenerate organometallic nucleophiles.
Assuntos
Iodo/química , Níquel/química , Nitrilas/química , Catálise , Oxirredução , EstereoisomerismoRESUMO
The first enantioselective Ni-catalyzed reductive acyl cross-coupling has been developed. Treatment of acid chlorides and racemic secondary benzyl chlorides with a Ni(II)/bis(oxazoline) catalyst in the presence of Mn(0) as a stoichiometric reductant generates acyclic α,α-disubstituted ketones in good yields and high enantioselectivity without requiring stoichiometric chiral auxiliaries or pregeneration of organometallic reagents. The mild, base-free reaction conditions are tolerant of a variety of functional groups on both coupling partners.