Indole C(4)-H Arylation And Alkylation And Related Tandem Reaction Studies

Multi-substituted-indoles are key building blocks in a large number of natural products,pharmaceuticals,and agrochemicals.Transition-metal-catalyzed directed C–H activation at the benzene moiety has emerged as a powerful synthetic approach to streamline the synthesis of indoles.It normally requires an adjacent directing group to tune the C–H functionalization sites,which leads to the generation of vicinal disubstituted indoles.However,direct formation of non-vicinal disubstituted indoles via the directing group’s assistance remains challenging.To achieve this goal,despite several directed remote C–H functionalization of indole have been developed,domino C–H functionalization/3,2-carbonyl migration of indoles formation of non-vicinal disubstituted indoles remains unsolved.Efficient C4-arylation and domino C4-arylation/3,2-carbonyl migration of indoles have been developed by tuning the distinct acid additives in the first part and the second part.The former route enables C4-arylation in a highly efficient and mild manner and the latter route provides an alternative straightforward protocol for synthesis of C2/C4 disubstituted indoles.C4-Alkylation and domino C4-alkylation /3,2-carbonyl migration of indoles has been developed by tuning temperature.