Addition of S−H Bonds across Electron-Deficient Olefins Catalyzed by Well-Defined Copper(I) Thiolate Complexes

Abstract

A series of monomeric (NHC)Cu(SR) (R = Ph or CH2Ph; NHC = N-heterocyclic carbene) complexes have been synthesized and fully characterized including single-crystal X-ray diffraction studies. These complexes catalyze the addition of S-H bonds across electron-deficient olefins to regioselectively produce "anti-Markovnikov" products.

A Cyclic Alkyl(amino)carbene as Two‐Atom π‐Chromophore Leading to the First Phosphorescent Linear CuI Complexes

“…where Ĥ SOC is the Hamiltonian of spin‐orbit coupling and FCWD is the Franck–Condon weighted density of states, which is proportional to exp[−(Δ E ST /4 k B T ) 2 ]. As the SOC of copper d electrons is much larger than that of the other elements involved, its strength between the coupling states can be estimated by a one‐centre SOC integral on the metal . In this approach, Ĥ SOC is non‐vanishing only for those transitions that differ in one, and only one, Cu d orbital.…”

Organometallic Approaches to Carbon–Sulfur Bond Formation

“…Gunnoe recently demonstrated the addition of thiols to electron-deficient alkenes using well-defined Cu-NHC thiolate complexes (31) [255,256]. The preliminary scope is broad, with a number of potentially reactive electron-withdrawing groups being well-tolerated.…”

“…Thiolation of electron-deficient alkenes with Cu-NHC thiolate complexes [255] Building from Krause's study with allenes,it was discovered that Au(I) catalysts can effect intermolecular hydrothiolation of unactivated olefins (32) [12]. 2-Mercaptoethanol reacts exclusively with sulfur, demonstrating chemoselectivity and functional group compatibility.…”

Synthesis of 1,3-Substituted Cyclobutanes by Allenoate-Alkene [2 + 2] Cycloaddition

“…24 Likewise, conjugate addition of PhSH yielded ester 35 with no evidence of transesterification of the phenyl ester. 25 The major diastereomer observed for both conjugate addition products resulted from addition of the nucleophile from the same face of the Ph group. To account for this mode of addition, we propose that the puckering of the cyclobutane ring and positioning of the Ph group in a pseudoequatorial orientation allows for the approach of reagents from the more accessible convex face as illustrated in Scheme 4.…”