Enantioselective Mannich-type reaction of sulfonylimines having 2-pyridylsulfonyl group as a novel stereocontroller

Stereoselective vinylation of aryl N-(2-pyridylsulfonyl) aldimines with 1-alkenyl-1,1-heterobimetallic reagents

Vinylation of aryl N-(2-pyridylsulfonyl) aldimines with versatile 1-alkenyl-1,1-borozinc heterobimetallic reagents is disclosed. In situ hydroboration of air-stable B(pin)-alkynes followed by chemoselective transmetalation with dimethylzinc and addition to aldimines provides B(pin)-substituted allylic amines in 53-93% yield in a one-pot procedure. The addition step can be followed by either B-C bond oxidation to provide α-amino ketones (71-98% yield) or Suzuki cross-coupling to furnish trisubstituted 2-arylated (E)-allylic amines (51-73% yield).

Catalytic enantioselective addition of diorganozinc reagents to vinyl sulfones

An efficient method for the catalytic asymmetric conjugate addition of diorganozinc reagents to vinyl sulfones is reported. Using a Binap*Cu complex, enantioselectivities up to 98% ee and high yields can be attained for a variety of substrates. Several dialkylzinc reagents are also compatible with this procedure.