Palladium-Catalyzed Olefination of Aryl C–H Bonds by Using Directing­ Scaffolds

Abstract

Site selective C-H bond activation/C-C bond formation is an ideal target for organic chemists owing to the ubiquitous nature of C-H bonds in natural products. A particular aryl C-H bond can be predictably activated by a directing group. However, the majority of strong and weak coordinating directing groups have been implemented for ortho-C-H bond activation/C-alkenylation. More recently, meta-C-H functionalization has been promoted by fine-tuning directing templates. In this short review, we have summarized recent progress in palladium-catalyzed directing group/template-assisted ortho/meta-C-H olefination. 1 Introduction 2 Proximal C-H Olefination 3 Distal C-H Olefination 4 Conclusions Key words palladium, directing groups, olefination, ortho/meta-C-H bond, removable auxiliary Sukdev Bag (left) received his B.Sc. degree in chemistry from West Bengal State University in 2011. He obtained his M.Sc. degree from IIT Bombay in 2013. He is now Ph.D. fellow in the research group of Prof. Debabrata Maiti at IIT Bombay. His research interests are in the area of metal-catalyzed C-H activation. Debabrata Maiti (right) received his Ph.D. from Johns Hopkins University (USA) in 2008 under the supervision of Prof. Kenneth D. Karlin. After postdoctoral studies at Massachusetts Institute of Technology (MIT) with Prof. Stephen L. Buchwald (2008-2010), he joined the Department of Chemistry of IIT Bombay in 2011. His research interests are focused on the development of new and sustainable synthetic methodologies.

Metal-Free Direct C–H Functionalization of Quinoxalin-2(1H)-Ones to Produce 3-Vinylated Quinoxalin-2(1H)-Ones in the Presence of Alkenes

“…We proposed the possible reaction mechanism based on these observations and the results presented in literature reports (Bag and Maiti, 2016;Gupta et al, 2017;Fu et al, 2018;Toonchue et al, 2018;Wei et al, 2018;Jin et al, 2019;Sekhar Dutta et al, 2019;Shen et al, 2019;Xie et al, 2019a,b;Zheng and Studer, 2019;Meng et al, 2020;Shi and Wei, 2020;Xie et al, 2020;Ali et al, 2021) (Scheme 5). Initially, alkene 2 reacts with sulfate radical anion (generated in situ) to generate the alkyl radical A.…”

Synthesis of N-isoindolinonyl peptides via Pd-catalyzed C(sp2)–H olefination–activation and their conformational studies

“…24,[45][46][47][48][49][50][51] Recently, Maiti has explored Pd-catalyzed 8-AQ-directed and template-based regioselective C-H olefinations with non-active aliphatic olefins. [47][48][49][50][51][52][53] Wang has demonstrated a Pd-catalyzed ortho-olefination reaction and cyclization reaction at benzylsufonamide to yield benzosultam peptidomimetics. 54 The synthesis of isoindolinone derivatives without comprising amino acids was accomplished from activated arylamides and non-reactive olefins through transition-metal-catalyzed C-H activation using metal ions Sc, Yb, Au, Rh, Ir, Ru, Co, Cu, Ni, Zn, In, and Pd (Fig.…”