Kim, Hyun Tae Ha, Hyeri Kang, Geunhee Kim, Og Soon Ryu, Ho Biswas, Abul Kalam Lim, Sang Min Baik, Mu-Hyun Joo, Jung Min 2024-01-20T00:00:26Z 2024-01-20T00:00:26Z 2021-09-03 2017-12-18 1433-7851 https://pubs.kist.re.kr/handle/201004/121909 Regioselective C4-, C5-, and di-alkenylations of pyrazoles were achieved. An electrophilic Pd catalyst generated by trifluoroacetic acid (TFA) and 4,5-diazafluoren-9-one (DAF) leads to C4-alkenylation, whereas KOAc and mono-protected amino acid (MPAA) ligand Ac-Val-OH give C5-alkenylation. A combination of palladium acetate, silver carbonate, and pivalic acid affords dialkenylation products. Annulation through sequential alkenylation, thermal 6 pi-electrocyclization, and oxidation gives functionalized indazoles. This comprehensive strategy greatly expands the range of readily accessible pyrazole and indazole derivatives, enabling useful regiodivergent C-H functionalization of pyrazoles and other heteroaromatic systems. English John Wiley & Sons Ltd. AMINO-ACID LIGANDS DIRECT ARYLATION ACTIVATION FUNCTIONALIZATION OXIDATION MECHANISM INDOLES ARENES AZOLES ROUTE Ligand-controlled Regiodivergent C-H Alkenylation of Pyrazoles and its Application to the Synthesis of Indazoles Article 10.1002/anie.201709162 1 Angewandte Chemie International Edition, v.56, no.51, pp.16262 - 16266 Angewandte Chemie International Edition 56 51 16262 16266 scie scopus 000419399800022 2-s2.0-85035147984 Chemistry, Multidisciplinary Chemistry Article AMINO-ACID LIGANDS DIRECT ARYLATION ACTIVATION FUNCTIONALIZATION OXIDATION MECHANISM INDOLES ARENES AZOLES ROUTE alkenylation C-H activation indazole palladium pyrazole