89241-39-4Relevant academic research and scientific papers
Synthesis and Diels-Alder Reactions of 1,3-Dimethyl-4-(phenylsulfonyl)-4H-furoindole. A new Annulation Strategy for the Construction of Ellipticine and Isoellipticine
Gribble, Gordon W.,Saulnier, Mark G.,Sibi, Mukund P.,Obaza-Nutaitis, Judy A.
, p. 4518 - 4523 (2007/10/02)
The novel fused heterocycle 1,3-dimethyl-4-(phenylsulfonyl)-4H-furoindole (4) is synthesized from 3-ethylindole (6) in six steps (46percent yield) or from indole-3-carboxaldehyde (12) in four steps (21percent yield).Furoindole 4 undergoes Diels-Alder reactions with dimethyl acetylenedicarboxylate, N-phenylmaleimide, benzyne, and 3,4-pyridyne (5) to give the expected adducts 17, 18a,b, 19, and 23a,b, respectively.Deoxygenation and desulfonylation of 19 and 23a,b, respectively, give benzocarbazole 22 and a readily separable mixture of the pyridocarbazole alkaloids ellipticine (1a) and isoellipticine (2a).
4-(PHENYLSULFONYL)-4H-FUROINDOLE - A STABLE SYNTHETIC ANALOGUE OF INDOLE-2,3-QUINODIMETHANE
Saulnier, Mark G.,Gribble, Gordon W.
, p. 5435 - 5438 (2007/10/02)
The N-phenylsulfonyl derivate (2) of the previously unknown fused heterocycle 4H-furo indole is synthesized from indole-3-carboxaldehyde (3) in 28percent yield and undergoes a Diels-Alder reaction with benzyne to give 5H-benzocarbazole (11) in 33percent yield after deoxygenation and deprotection.
