Transition-Metal-Free Access to Pyridocarbazoles from 2‑Alkynylindole-3-carbaldehydes via Azomethine Ylide
datasetposted on 23.05.2018, 00:00 authored by Shalini Verma, Pawan K. Mishra, Manoj Kumar, Souvik Sur, Akhilesh K. Verma
An efficient approach for the synthesis of functionalized tetrahydro-pyrido/quinolinocarbazoles from 2-alkynylindole-3-carbaldehydes and l-proline utilizing a metal-free decarboxylative cyclization, ring expansion, and ring contraction strategy via the generation of azomethine ylide was developed. The reaction of 2-alkynylindole-3-carbaldehydes with l-thioproline leads to the formation of γ-carbolines. By virtue of this expedient method, a diverse range of biologically active heteroannulated carbazoles can be synthesized efficiently.