Synthesis of Indolo[2,1-a]benzazepinones through Rhodium-Catalyzed Cascade Reactions of 2-Arylindoles with Allyl Alcohols

Abstract

An efficient synthesis of indolo­[2,1-a]­benzazepinones through rhodium-catalyzed cascade reactions of 2-arylindoles with allyl alcohols has been developed. This work expands the scope of products that are available through C–H activation/intramolecular annulation reactions of 2-arylindoles in organic synthesis.

Palladium-Catalyzed C–H Allylation/Annulation Reaction of Amides and Allylic Alcohols: Regioselective Construction of Vinyl-Substituted 3,4-Dihydroisoquinolones

“…Another powerful strategy in organic synthesis is the transition-metal-catalyzed C–H functionalization, especially the C–H functionalization/annulation reactions, which provide rapid construction of valuable cyclic products via atom- and step-economically benign routes from easily accessible starting materials. However, the transition-metal-catalyzed C–H functionalization/annulation reaction suffers from poor regioselectivities . Hence, the development of highly regioselective C–H allylation/annulation reaction with nonactivated allylic alcohols is challenging and rewarding.…”

1-Acryloyl-2-cyanoindole: A Skeleton for Visible-Light-Induced Cascade Annulation

“…For example, some representative examples such as flinderole B (antimalarial), melatonin (neuroendocrine immunoregulatory activity), JTT-010 (protein kinase C-β isoform-selective inhibitor), and yuremamine (hallucinogenic and psychoactive) are shown in Figure . Therefore, the development of novel and efficient strategies to synthesize pyrrolo­[1,2- a ]­indole derivatives is highly desirable for facilitating the discovery of new bioactive molecules …”

Palladium-Catalyzed Three-Component Regioselective Dehydrogenative Coupling of Indoles, 2-Methylbut-2-ene, and Carboxylic Acids

“…In addition, we observed a peak ([C 16 H 13 NNaO 2 Pd] + , m / z 379.9879; see the Supporting Information) in high-resolution mass spectrometry (HRMS) of the reaction system of compound 1a . The two experiments indicated the possibility of C3 palladation of indole . Finally, the kinetic experiments were conducted to examine the influence of the amount of acid on the competitive reactions (see the Supporting Information).…”

“…The two experiments indicated the possibility of C3 palladation of indole. 23 Finally, the kinetic experiments were conducted to examine the influence of the amount of acid on the competitive reactions (see the Supporting Information). The amount of acetate acid less than 11 equiv was prone to allylation, and more than 11 equiv was beneficial to the threecomponent reactions.…”