Palladium(ii)-catalyzed synthesis of dibenzothiophene derivatives via the cleavage of carbon–sulfur and carbon–hydrogen bonds

Abstract

Pd(ii)-catalyzed synthesis of dibenzothiophene derivatives has been developed. The reaction proceeds through the cleavage of carbon–hydrogen and carbon–sulfur bonds.

A comprehensive overview of directing groups applied in metal-catalysed C–H functionalisation chemistry

“…Thiol-directed C–H activation can also be astutely used to access benzo-fused thiophenes via intramolecular C–H arylation, as illustrated in 2016 by Tobisu and Chatani ( Scheme 162C ). 1006 The authors discovered that biphenylsulfide, in the presence of Pd(OAc) 2 and under carboxylic acid assistance (2,6-Me 2 C 6 H 3 CO 2 H used) undergoes a tandem C–H cleavage/intramolecular C–S bond formation/S–C cleavage, delivering the desired heterocyclic products under oxidant-free conditions. This operationally simple and high-yielding protocol using readily accessible starting materials and reactants gives access to a large panel of unsymmetrical dibenzothiophenes, important scaffolds in advanced material science and bioactive molecules.…”

Palladium(II)‐Catalyzed Synthesis of Dibenzothiophenes from 2‐Biphenylyl Disulfides by C−H Functionalization

“…[12] Moreover,Z hao and Liu described the transitionmetal-catalyzed preparation of dibenzothiophene derivatives through the intramolecular dehydrogenative CÀH/CÀHc oupling of diaryl sulfides (path ci nS cheme 1). [14] These synthetic methodsh ave enabled the provision of dibenzothiophenes bearingv ersatile functionalg roups.H owever,t hese synthetic methods generally requiree ssential additives, such as ametal oxidant, aligand or abase to drive the desired cyclization. [14] These synthetic methodsh ave enabled the provision of dibenzothiophenes bearingv ersatile functionalg roups.H owever,t hese synthetic methods generally requiree ssential additives, such as ametal oxidant, aligand or abase to drive the desired cyclization.…”

“…[13] On the other hand,T obisu, Chatani, and co-workershave describedapalladium-catalyzed CÀH/CÀSc oupling of biphenylyl sulfides leading to dibenzothiophene derivatives (path di nS cheme 1). [14] These synthetic methodsh ave enabled the provision of dibenzothiophenes bearingv ersatile functionalg roups.H owever,t hese synthetic methods generally requiree ssential additives, such as ametal oxidant, aligand or abase to drive the desired cyclization.…”

Catalytic Synthesis of Heterocycles via the Cleavage of Carbon-Heteroatom Bonds

“…The desired reaction, in fact, proceeded under palladium(II) catalyzed conditions when a biaryl sul de 75 was used. 49 The addition of bulky benzoic acid derivative (2,6 Me 2 C 6 H 3 CO 2 H) was found to improve the yield signi cantly. Regarding the leaving group on the sulfur atom, the use of a phenyl group is essential for an ef cient reaction, with only 7% of the product being formed when a substrate bearing a methylthio group was used.…”