Stereoselective Vinylation of Aryl N-(2-Pyridylsulfonyl) Aldimines with 1-Alkenyl-1,1-heterobimetallic Reagents

Abstract

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 transmetallation with dimethylzinc and addition to aldimines provides B(pin)-substituted allylic amines in 60–93% 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).

Outer-Sphere Direction in Iridium C–H Borylation

“…Remarkably, the Ph C–H bonds and the stereochemistry of the double bond in product 21 are unperturbed. Recent reports reflect interest in borylenamines and related compounds, 17 including a route using C-H borylation, 17c but the reaction here provides a cis disposition of N and B groups that is unavailable by other methods.…”

Base‐Catalyzed NN Bond Cleavage of Hydrazones: Synthesis of α‐Amino Ketones

“…11 However, secondary α‐sulfonylamino ketones 4 cannot be prepared directly from sulfamide and 2‐bromoacetophenone 12. These types of α‐amino ketones are constructed from the ring‐opening of aziridines10a–d or the oxidation of allylic amines 10e. Very recently, the rhodium‐catalyzed denitrogenative hydration of N ‐sulfonyl‐1,2,3‐triazoles to α‐sulfonylamino ketones was reported by Murakami and co‐workers 10f.…”