B(C₆F₅)₃-Catalyzed Reductive Denitrogenation of Benzonitrile Derivatives

Abstract

A B(C 6 F 5 ) 3 -catalyzed reductive denitrogenation of aromatic nitriles is reported, achieving the metal-free transformation of a cyano into a methyl group in a single synthetic operation. Tris(phenylsilyl)amine is liberated as the nitrogen-containing byproduct. On the basis of control experiments as well as a nuclear magnetic resonance spectroscopic analysis, an S N 1-type mechanism involving a trisilylammonium ion as a key intermediate is proposed.

Structural and Electronic Effects on Phosphine Chalcogenide Stabilized Silicon Centers in Four-Membered Heterocyclic Cations

“…According to NMR spectroscopic analysis, the reaction products were unambiguously identified as the hydrosilylated nitriles 16 and 17 , respectively, and the borane–nitrile adduct 18 formed in an approximate 1:1 ratio with 0.5 equiv of unreacted starting material left (either 7 [HB­(C 6 F 5 ) 3 ] or 8 [HB­(C 6 F 5 ) 3 ]). B­(C 6 F 5 ) 3 -catalyzed reductive silylation of nitriles to afford imines and amines, and denitrogenation of aromatic nitriles have been reported previously. Notably, the six-membered cyclic siloxane-based cations in combination with hydroborate counterions, which were recently synthesized in our group, did not show a hydrosilylation reaction with p -FBN, indicating a higher Lewis acidity of the four-membered cyclic cations and also supporting the previously observed robustness of the siloxane-based systems …”

Au nanoparticle-catalyzed double hydrosilylation of nitriles by diethylsilane

“…In the less common, hydrodecyanation 6 or complete reduction of the cyano functionality into a methyl group may occur. 7 The most common pathways are monohydrosilylation leading to N -silylated imines, 8 or depending on the catalyst, an additional hydrosilylation may occur leading to N -disilylamines. N -Silylamines 9 can be readily deprotected to primary amines.…”

Achieving Site-Selective C–O Bond Reduction for High-Value Cellulosic Valorization

“…27,34−36 These observations were foundational to our studies on site selective C−O bond reduction in carbohydrates, the topic of this Perspective, and have led to reduction of bonds beyond C−O such as C−N cleavage which is not covered in detail here. 37…”

“…Unlike BF 3 (3° > 2° > 1°), the observed trend implied an S N 2 C–O cleavage step. Further studies revealed that hydrodeoxygenation of 2° and 3° C–O bonds was possible with more reactive Et 2 SiH 2 and n BuSiH 3 or through allylic or benzylic stabilization of putative carbocation intermediates. ,− These observations were foundational to our studies on site selective C–O bond reduction in carbohydrates, the topic of this Perspective, and have led to reduction of bonds beyond C–O such as C–N cleavage which is not covered in detail here …”