Tetrahedron

Synthesis, structure and AM1 conformational study of [3] paracyclo [3](1, 3) indolophane, a novel chiral cyclophane

GJ Bodwell, J Li, DO Miller

Index: Bodwell, Graham J.; Li, Jiang; Miller, David O. Tetrahedron, 1999 , vol. 55, # 45 p. 12939 - 12956

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Citation Number: 33

Abstract

The title compound 5 was synthesized in seven steps with an overall yield of 22%. The two bridges were formed by a conjugate addition of indole to a Michael acceptor and by an intramolecular N-alkylation, respectively. A dynamic NMR study revealed the presence of a conformational process with an activation barrier of 10.9±0.2 kcal/mol, which was assigned to a ring flipping process that interconverts two enantiomeric sets of equilibrating bridge ...