Pd -Catalyzed Asymmetric Carbonitratation Reaction Featuring an H-Bonding-Driven Alkyl-Pd -ONO Reductive Elimination.

Reductive elimination of alkyl-Pd -O is a synthetically useful yet underdeveloped elementary reaction. Here we report that the combination of an H-bonding donor [PyH][BF ] and AgNO additive under toluene/H O biphasic system can enable such elementary step to form alkyl nitrate. This results in the Pd -catalyzed asymmetric carbonitratations of (Z)-1-iodo-1,6-dienes with (R)-BINAP as the chiral ligand, affording alkyl nitrates up to 96 % ee. Mechanistic studies disclose that the reaction consists of oxidative addition of Pd catalyst to vinyl iodide, anion ligand exchange between I and NO , alkene insertion and S 2-type alkyl-Pd -ONO reductive elimination. Evidences suggest that H-bonding interaction of PyH⋅⋅⋅ONO can facilitate dissociation of O NO ligand from the alkyl-Pd -ONO species, thus enabling the challenging alkyl-Pd -ONO reductive elimination to be feasible.