Tetrahedron letters

Pictet-Spengler condensation of N-sulfonyl-β-phenethylamines with α-chloro-α-phenylselenoesters. New synthesis of 1, 2, 3, 4-tetrahydroisoquinoline-1-carboxylates

CC Silveira, CR Bernardi, AL Braga, TS Kaufman

Index: Silveira, Claudio C.; Bernardi, Carmem R.; Braga, Antonio L.; Kaufman, Teodoro S. Tetrahedron Letters, 1999 , vol. 40, # 27 p. 4969 - 4972

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Citation Number: 23

Abstract

The reaction of N-sulfonyl-β-phenethylamines with α-chloro-α-phenylseleno acetate/propionate esters under Lewis acid promotion gives moderate to good yields of the corresponding 1, 2, 3, 4-tetrahydroisoquinoline-1-carboxylates. Varying degrees of diastereoselection were obtained using chiral sulfonamides and/or esters. Employing this strategy, the achievement of a new total synthesis of Calycotomine is reported.