Nickel-Catalyzed Coupling of Azoles with Aromatic Nitriles

Abstract

This manuscript describes the Ni-catalyzed coupling of azoles with aromatic nitriles. The use of BPh3 promotes these arylations with electronically diverse oxazoles and benzonitriles. While the nickel catalyst is necessary for the arylations of phenyl oxazoles, arylation of benzoxazoles with some nitriles affords the arylated products even in the absence of the Ni-catalyst albeit in lower yield than the catalyzed process. The scope and rates of the Ni-catalyzed process are higher than the uncatalyzed transformation.

Cobalt(II) nitrate promoted cyclization of benzoyl hydrazone for the synthesis of 2,5-diphenyl-1,3,4-oxadiazole derivatives

“…4,5 In view of their great importance, the synthesis of 2,5-diaryl-1,3,4-oxadiazoles has gained much attention in recent decades and many useful synthetic procedures for their preparation have been developed. For example, arylation of 1,3,4-oxadiazoles (Scheme 1(a)), [6][7][8] aminocarbonylation reaction of aryl halides with chloroform and tetrazoles (Scheme 1(b)), [9][10][11][12] oxidative dehydrogenation of N-substituted hydrazides (Scheme 1(c)), 13 oxidations of aldehyde hydrazones and N, N-dimethylamides (Scheme 1(d)), 14 isocyanide insertion/cyclization sequence of hydrazides and aryl halide (Scheme 1(e)), 15 the use of Vilsmeier's reagent (Scheme 1(f)), 16,17 decarboxylation and cyclization of α-keto acids with acylhydrazines (Scheme 1(g)), 18,19 oxidative cyclization using aldehydes and acyl hydrazides (Scheme 1(h)). [20][21][22][23][24][25][26][27][28][29][30][31] As shown in Scheme 2, many different methods have been developed for the synthesis of 2,5-substituted-1,3,4-oxadiazoles from aldehydes and acyl hydrazides (Scheme 1(h)).…”

Recent Advances on Synthetic Methodology Merging C–H Functionalization and C–C Cleavage

“…The C–CN bond activation constitutes an interesting approach for the use of nitriles as coupling partners [ 130 ]. Kalyani and co-workers reported a protocol for the C–H arylation of azoles 367 utilizing benzonitriles 368 as the arylating reagents ( Scheme 48 ) [ 131 ]. The reaction was carried out employing a 20 mol% of [Ni(COD) 2 ]/dcype as catalyst.…”

Decyanative Cross‐Coupling of Cyanopyrimidines with O‐, S‐, and N‐Nucleophiles: A Route to Alkoxylpyrimidines, Aminopyrimidines and Alkylthiopyrimidines

“…Since Miller first reported the synthesis of unsymmetrical biaryls via the cross‐coupling of aryl nitriles with Grignard reagents using a phosphine‐based Ni catalyst, continued attention has been paid to decyanative cross‐coupling reactions . Recently, Kalyani described a Ni‐catalyzed cross‐coupling of aryl nitriles with azoles by using the corresponding ligand and BPh 3 at 140 °C (Scheme a) , . Chatani demonstrated a Rh I ‐catalyzed silylation reaction of aryl cyanides with hexamethyldisilane involving the cleavage of Ar–CN and Si–Si bonds (Scheme b) .…”