Nickel‐Catalyzed Suzuki–Miyaura Coupling of a Tertiary Iodocyclopropane with Wide Boronic Acid Substrate Scope: Coupling Reaction Outcome Depends on Radical Species Stability

Abstract

This is the first transition metal‐catalyzed Suzuki—Miyaura coupling reaction between a tertiary alkyl halide and a wide variety of aromatic boronic acids.

Tertiary Alkylative Suzuki–Miyaura Couplings

“…A Ni catalyst is also effective for bicyclic electrophiles. Arisawa and Shuto's group reported S-M coupling of racemic cyclopropane-derived bicyclic iodide (3.1) and aryl boronic acid (3.2) in the presence of Ni(PCy3)2Cl2 as a catalyst (Scheme 3) [4].…”

“…Arisawa and Shuto’s group reported S-M coupling of racemic cyclopropane-derived bicyclic iodide 3.1 and aryl boronic acid 3.2 in the presence of Ni(PCy 3 ) 2 Cl 2 as a catalyst (Scheme 3 ). 4 In this case, the authors successfully employed easily available aryl boronic acids as the aryl source to produce coupling products 3.3a – d in good yields.…”

The Cyclopropane Ring as a Reporter of Radical Leaving-Group Reactivity for Ni-Catalyzed C(sp3)–O Arylation

“…Thus, the one-electron substitution process can retain the cyclopropane ring. In the context of Ni catalysis, a number of redox-active leaving groups have been employed for cyclopropane functionalization, including iodides, bromides, N -hydroxyphthalimide esters (derived from carboxylic acids), and pyridinium salts (derived from cyclopropylamines) (Figure b). − …”

“…12 Thus, the one-electron substitution process can retain the cyclopropane ring. In the context of Ni catalysis, a number of redox-active leaving groups have been employed for cyclopropane functionalization, including iodides, 13 bromides, 14 N-hydroxyphthalimide esters (derived from carboxylic acids), 15 and pyridinium salts (derived from cyclopropylamines) (Figure 1b). 16−18 For the Ni-catalyzed C(sp 3 )−O functionalization reaction of cyclopropanols, the product distribution would directly reflect the reactivity of the leaving group (Figure 1c redox-active leaving group.…”

The Cyclopropane Ring as a Reporter of Radical Leaving-Group Reactivity for Ni-Catalyzed C(sp3)–O Arylation

“…12 Thus, one-electron substitution process can retain the cyclopropane ring. In the context of Ni catalysis, a number of redox-active leaving groups have been employed for cyclopropane functionalization, including iodides, 13 bromides, 14 N-hydroxyphthalimide esters (derived from carboxylic acids), 15 and pyridinium salts (derived from cyclopropylamines) (Figure 1b). 16,17,18 For the Ni-catalyzed C(sp 3 )-O functionalization reaction of cyclopropanols, the product distribution would directly reflect the reactivity of the leaving group (Figure 1c, right arrow), with the arylcyclopropane product being obtained from a redox-active leaving group.…”