Reductive C−C Coupling from α,β‐Unsaturated Nitriles by Intercepting Keteniminates

Abstract

We present an atom‐economic strategy to catalytically generate and intercept nitrile anion equivalents using hydrogen transfer catalysis. Addition of α,β‐unsaturated nitriles to a pincer‐based Ru−H complex affords structurally characterized κ‐N‐coordinated keteniminates by selective 1,4‐hydride transfer. When generated in situ under catalytic hydrogenation conditions, electrophilic addition to the keteniminate was achieved using anhydrides to provide α‐cyanoacetates in high yields. This work represents a new application of hydrogen transfer catalysis using α,β‐unsaturated nitriles for reductive C−C coupling reactions.

Ene Reactivity of an Fe═NR Bond Enables the Catalytic α-Deuteration of Nitriles and Alkynes

“…The Fe–N­(keteniminate) bond distance (2.030(2) Å) is similar to those observed in high-spin iron­(II) amido complexes . Interestingly, the keteniminate Fe–N–C angle (128.2(2)°) shows a large deviation from linearity, in contrast to other keteniminate complexes. − …”

Catalytic Conversion of Nitriles by Metal Pincer Complexes

“…Szymczak and co-workers reported the hydrogenative acylation of α,β-unsaturated nitriles catalysed by a ruthenium pincer complex [53]. The reaction, which was performed with 4 eq.…”

Catalytic Olefin Transpositions Facilitated by Ruthenium N,N,N-Pincer Complexes

“…We have developed a family of N,N,N-pincer ruthenium catalysts capable of performing diverse chemical transformations. The exceptional reactivity of one of these catalysts, HRu(bMepi)(PPh3)2 (hereafter 6-RuH), has been showcased in alcohol and amine dehydrogenations, [19][20][21][22][23] olefin hydroacylations 24 , Guerbet reactions, 25,26 and alkyne/alkene hydrogenation. 27 Modification of the pyridyl pincer arms or the isoindolate backbone of the N,N,N-pincer ligand framework allows for greater diversity of reactivity including nitrile difunctionalization, 28 selective alkyne semi-hydrogenation, 27 and deuteration of chiral amines.…”