An efficient domino one-pot synthesis of novel spirofuran-indenoquinoxalines by vinyltriphenylphosphonium salts

Abstract

A simple and convenient multi-component domino reaction has been described for the synthesis of novel spirofuran-indenoquinoxaline derivatives. Products were obtained by a three-component condensation reaction between ninhydrin, aromatic 1,2-diamines and dialkyl ethynedicarboxylates in the presence of a catalytic amount of triphenylphosphine in CH 2 Cl 2 at ambient temperature in excellent yields. This one-pot process produces biologically and pharmacologically significant heterocycles with the formation of five new bonds (one CC , two C=N and two CO) and two new rings in a single operation.

Zn(L-proline)2: An efficient and reusable organocatalyst for the synthesis of polyfunctionally substituted pyrans and 2-amino-4-aryl-8-oxo-4,8-dihydropyrano[3,2-b]pyran derivatives

“…Multi-component reactions (MCRs) have major advantages that relied in the synthesis of complex molecules from simple molecules [17,18].…”

Multisulfonate hyperbranched polyglycerol functionalized graphene oxide as an efficient reusable catalyst for green synthesis of benzo[a]pyrano-[2,3-c]phenazines under solvent-free conditions

“…A number of methods have been reported for the synthesis of benzo[a]pyrano [2,3-c]phenazine. The synthesis of benzo[a]pyrano[2,3-c]phenazine is carried out with various catalysts such as acetic acid, 25 nano copper(II) oxide, 26 ionic liquid, 27 theophylline, 28 and DABCO. 12 Most of these catalysts have drawbacks, such as corrosive, non-reusable, and non-recoverable.…”

Green synthesis of novel pyrazolo‐fused benzophenazines using H3PW12O40 as efficient and recyclable catalyst under microwave irradiation

“…Considering the significant potential of novel pyrazole and benzophenazine derivatives as a source of valuable drug candidates, together with our continued interest on MCRs and our ongoing program for the synthesis of a wide range of complex organic compounds based on green chemistry protocols, here we report a green and efficient method for the synthesis of novel 11 H ‐benzo[ a ]pyrazolo[3,4‐ c ]phenazines ( 6) through a single‐pot multicomponent condensation reaction between 2‐hydroxy‐1,4‐naphthoquinone ( 1 ), o ‐phenylenediamine ( 2 ), aromatic aldehydes ( 4 ), and 4‐methylbenzenesulfonohydrazide ( 5 ) catalyzed by phosphotungstic acid (H 3 PW 12 O 40 ) as a highly efficient, eco‐friendly, and recyclable solid heteropolyacid catalyst under microwave irradiation (MWI) (180 W, max. 70 °C) in EtOH (Scheme ).…”