Benzimidazole bearing Pd–PEPPSI complexes catalyzed direct C2‐arylation/heteroarylation ofN‐substituted benzimidazoles

Abstract

A convenient and highly efficient palladium‐catalyzed direct C2‐arylation/heteroarylation of N‐substituted benzimidazole derivatives such as N‐benzyl/3‐chlorobenzyl/2,4,6‐trimethylbenzyl/2,4,6‐triisopropylbenzyl/aryl benzimidazoles with various aryl/heteroaryl bromides in the presence of Pd–PEPPSI (palladium‐pyridine enhanced pre‐catalyst preparation stabilization and initiation) complexes is reported. In order to that we have prepared a series of different symmetrical and unsymmetrical N,N′‐diaralkyl benzimidazole‐bearing Pd–PEPPSI complexes. Among all of the the prepared complexes, Pd–PEPPSI‐3 effectively tuned the reaction at a relatively higher rate under mild reaction conditions in an ethanol–water system. In addition, the catalytic process avoids the use of external ligand and additives. Further the reactivity was compared with commercially available copper‐N‐heterocyclic carbene catalyst, but the reaction was less successful. With the optimized reaction conditions, a wide range of 2‐aryl/heteroaryl‐N‐substituted benzimidazoles were synthesized in good to excellent yields via Csp2‐H/Csp2‐X biaryl cross‐coupling.

Sustainable protocols for direct C–H bond arylation of (hetero)arenes

“…173 The only report on the direct arylation of benzimidazoles in aqueous conditions was described in 2020 by Peddiahgari and co-workers: a family of Pd-PEPPSI complexes was tested in the direct C2 arylation of N-substituted benzimidazoles in a water/ ethanol 1 : 1 (v/v) mixture. 174 However, this work was actually mainly focused on the synthesis and catalytic performance of such complexes, rather than on the development of a highly sustainable direct C-H arylation protocol of benzimidazoles.…”

Green Synthesis, Antioxidant, and Plant Growth Regulatory Activities of Novel α-Furfuryl-2-alkylaminophosphonates

“…31 In organic chemistry, 32 they have been used as catalysts 33 in coupling 34 and complex reactions 35 and also as catalytic promoters. 36 Many aminophosphonic acids/peptides/ esters from both synthetic and natural origin have displayed an extensive array of biological activities. 37 They act as substrates in the synthesis and development of impending drugs against various metabolic disorders.…”

“…In the industry, they are used as additive polymers, surfactants, lubricants, surface treaters on metals, and flame retardants . In organic chemistry, they have been used as catalysts in coupling and complex reactions and also as catalytic promoters . Many aminophosphonic acids/peptides/esters from both synthetic and natural origin have displayed an extensive array of biological activities .…”

Synthesis and Anti-Pancreatic Cancer Activity Studies of Novel 3-Amino-2-hydroxybenzofused 2-Phospha-γ-lactones

“…Organophosphorus chemistry has offered many catalysts for the successful accomplishments of complex 1 and coupling 2 reactions by the action of potential catalyst promoters. 3 In medicinal perspectives, some of them have been identified as potential antioxidant, 4 antifungal, 5 antibacterial, 6 − 8 antidiabetic, 9 anticancer, 10 antithrombotic, 11 and antimicrobial 12 agents. Their re-emergence in the field of medicinal chemistry made it amplified as many of them were impregnated with potential moieties in its design itself 13 and identified with a wide array of applications.…”

“…Organophosphorus chemistry has offered many catalysts for the successful accomplishments of complex and coupling reactions by the action of potential catalyst promoters . In medicinal perspectives, some of them have been identified as potential antioxidant, antifungal, antibacterial, − antidiabetic, anticancer, antithrombotic, and antimicrobial agents.…”