RhCl₃-Catalyzed Oxidative C–H/C–H Cross-Coupling of (Hetero)aromatic Sulfonamides with (Hetero)arenes

Abstract

1,1′-Bi(hetero)aryl 2-sulfonamide scaffolds have been widely used as a privileged structure in drug discovery. Herein, we report an efficient rhodium-catalyzed oxidative C−H/ C−H cross-coupling between a (hetero)aromatic sulfonamide and a (hetero)arene to afford ortho-sulfonamido bi(hetero)aryls. This methodology features broad substrate scope, good functional group tolerance, and relatively inexpensive catalyst (without the use of RhCp*). A wide range of (hetero)arenes such as thiophenes, benzothiophenes, pyrroles, furans, benzofuran, indolizine, and simple arenes can engage in this transformation. This protocol also provides a facile route to bi(hetero)aryl sultams and dibenzo[b,d]thiophene 5,5-dioxides through further intramolecular cyclization, indicating its potential application in materials exploitation.

Switching the site-selectivity of C–H activation in aryl sulfonamides containing strongly coordinating N-heterocycles

“…2A). [44][45][46] In this study, we successfully switched the selectivity of the C-H carbenoid functionalization 47-66 of sulfonamides [67][68][69][70][71][72][73][74][75][76][77][78][79][80] containing N-heterocycles 81 using a rhodium catalyst. The selectivity was precisely controlled by changing the reaction medium polarity and additive concentration, affording C-H activation at the ortho position relative to the N-heterocycle (charge-neutral forms, denoted as L-type ligands) or sulfonamide (easily deprotonated to charge-negative forms, denoted as X-type ligands) directing groups.…”

Rhodium-catalyzed ortho-heteroarylation of phenols: directing group-enabled switching of the electronic bias for heteroaromatic coupling partner

“…Considering the wide application of thiophene-based scaffolds, 1e , 2 we initially selected the cross-coupling between phenol derivatives ( 1 ) and electron-rich benzothiophene ( 2a ) as a model reaction. 8 At the outset of our investigation, we tested the feasibility of oxidative C–H/C–H cross-coupling between phenol and benzothiophene under the privileged [Cp*RhCl 2 ] 2 /AgSbF 6 catalytic system, using the commonly used O -carbamate, acyloxy, oxyacetamide and tosyl as the directing groups ( Scheme 3 ). However, these directing groups were incapable of promoting the oxidative coupling reactions.…”

Recent Advances in Catalytic Synthesis of Benzosultams

“…Then, Li and Wang et al extended this strategy to the oxidative coupling of N -tosylacetamide with various acrylate esters for the preparation of five-membered cyclic benzosultams [ 59 ]. Using RuCl 3 as an efficient catalyst, in 2018, You and colleagues disclosed a direct oxidative C–H/C–H cross-coupling of (hetero)aromatic sulfonamides with a series of (hetero)arenes for the synthesis of ortho -sulfonamido bi(hetero)aryls [ 60 ]. The obtained bi(hetero)aryl sulfonamides could be conveniently transferred into benzosultam derivatives in two steps.…”