Diastereoselective synthesis of functionalized tetrahydro-γ-carbolines via a [3 + 3] cycloaddition of 2,2′-diester aziridines with β-(indol-2-yl)-α,β-unsaturated ketones

Synthesis of Pyridazino[4,5-b]indoles by [3+3] Annulation of 2-Alkenylindoles and Hydrazonyl Chlorides

A novel [3+3] annulation reaction of 2-alkenylindoles with hydrazonyl chlorides in the presence of base for the formation of pyridazino[4,5-b]indoles was developed. This approach provided a convenient and efficient way to synthesize a series of functionalized pyridazino[4,5-b]indoles derivatives. The method exhibited a broad substrate scope and provided the corresponding pyridazino[4,5-b]indoles products with excellent yields.

Arylsulfonylation-Triggered Cyclization of 3-Alkenyl Indoles Enabling Synthesis of Tetrahydro-γ-carboline

A visible-light promoted cyclization reaction of 3-alkenyl indole derivatives with arylsulfonyl chlorides as coupling partners has been developed, which afforded functionalized tetrahydro-γ-carbolines in good chemical yields. The reaction used 3-alkenyl indoles as radical acceptors and proceeded via the sequence of sulfonylation and intramolecular cyclization. The reaction was carried out under mild conditions and tolerated a wide range of substrates, which provides an efficient strategy for the synthesis of tetrahydro-γ-carboline derivatives.

Multicomponent synthesis of novel β-carboline-fused imidazolium derivatives via the Mannich reaction: cytotoxicity, molecular docking, and mechanistic studies as angiogenesis inhibitors

Herein we report novel multicomponent reactions for the synthesis of β-carboline-fused imidazolium derivatives via the Mannich-type reaction.

Synthesis of polycyclic spiroindolines via the cascade reaction of 3-(2-isocyanoethyl)indoles

Tandem reactions of the yttrium(iii) catalyzed ring-opening reaction of 2,2'-diester aziridines with 3-(2-isocyanoethyl)indoles and the subsequent Friedel-Crafts/Mannich/desulfonylation were reported. A series of polycyclic spiroindolines containing tetrahydro-β-carbolines were obtained in moderate to excellent yields (56-92%) in one step under mild reaction conditions. A possible catalytic mechanism was also proposed.

Sc(OTf)3 catalyzed [3 + 2]-annulation reaction of donor–acceptor aziridines with methylene exo-glycals: synthesis of chiral carbohydrate-spiro-heterocycles

A Sc(OTf)₃ catalyzed [3 + 2]-annulation reaction between D–A N-tosyl aziridines and methylene exo-glycals was developed for the synthesis of carbohydrate-spiro-heterocycles.

Synthesis of 1-benzylisoindoline and 1-benzyl-tetrahydroisoquinoline through nucleophilic addition of organozinc reagents to N,O-acetals

A new approach to access 1-benzylisoindoline and 1-benzyl-tetrahydroisoquinoline has been developed through nucleophilic addition of organozinc reagents to N,O-acetals. A number of substituted organozinc reagents were amenable for this transformation, and the desired products were obtained with excellent yields. Moreover, Sc(OTf)3 proved to be an effective catalyst for the formation of 1-benzylisoindoline and 1-benzyl-tetrahydroisoquinoline using such nucleophilic addition.

Copper(i)-catalyzed asymmetric [3 + 3] annulation involving aziridines to construct tetrahydro-β-carbolines

A copper-catalyzed asymmetric [3 + 3] annulation of 2-vinylindoles with 2-aryl aziridines has been described, providing direct access to enantioenriched tetrahydro-β-carbolines.