Nickel-Catalyzed Decarboxylative Coupling of Alkynyl Carboxylates with Aryl Tosylates and Mesylates

Abstract

A method for the nickel-catalyzed coupling of alkynyl carboxylates or acids with aryl tosylates and mesylates is described. Electronically varied carboxylates and aryl electrophiles participate in these transformations to afford the desired diarylalkyne products. In general, electrophiles bearing an extended π-system lead to products in higher yields than sulfonates with only one aromatic ring.

Nickel‐Catalysed Decarboxylative Coupling Reactions – An Overview

“…In 2018, Kalyani et al described the first practical example of Ni-catalysed decarboxylative cross-coupling of alkynyl acids or carboxylates 113 with aryl tosylates 114 and mesylates 115. [56] They performed the coupling of alkynyl carboxylates 113 with aryl tosylates 114 and mesylates 115 using Ni(COD) 2 (10 mol %) as a catalyst and PMe 3 HBF 4 (30 mol %) as the ligand in dioxane or diglyme as the solvent in 80-140 °C to furnish the diarylalkyne products 106 in good to excellent (47-99 %) yields. (Scheme 37).…”

Recent advances in catalytic decarboxylative transformations of carboxylic acid groups attached to a non-aromatic sp2or sp carbon

“…Later, Kalyani et al demonstrated that not only palladium, but also a nickel based catalyst system was able to promote the decarboxylative cross-coupling of alkynyl carboxylates with aryl tosylate 139b and mesylates (Table 4, entry 3). 73…”

“…Later, Kalyani et al demonstrated that not only palladium, but also a nickel based catalyst system was able to promote the decarboxylative cross-coupling of alkynyl carboxylates with aryl tosylate 139b and mesylates (Table 4, entry 3). 73 In 2017, Schnürch et al disclosed an efficient strategy for the C1-selective alkynylation of N-arylated 1,2,3,4-tetrahydroisoquinolines 181 with propiolic acids 172 by means of a copper/TBHP-based catalyst system (Scheme 57). 74 Importantly, the reaction is equally competent for the installation of both aromatic and aliphatic alkynes.…”