Synthesis of Triazolo Isoquinolines and Isochromenes from 2-Alkynylbenzaldehyde via Domino Reactions under Transition-Metal-Free Conditions

RK Arigela, S Samala, R Mahar…

Index: Arigela, Rajesh K.; Samala, Srinivas; Mahar, Rohit; Shukla, Sanjeev K.; Kundu, Bijoy Journal of Organic Chemistry, 2013 , vol. 78, # 20 p. 10476 - 10484

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Citation Number: 22

Abstract

We describe two simple straightforward syntheses of triazolo isoquinolines (3) and isochromenes (7) from 2-alkynylbenzaldehydes (1) as a common synthon. The synthetic strategy for 3 involves formation of the (E)-1-(2-nitrovinyl)-2-(alkynyl) benzene species 2 via condensation of synthon 1 with nitromethane followed by a [3+ 2] cycloaddition/extrusion of the nitro group/regioselective 6-endo cyclization domino sequence. In yet another strategy ...