PHOTOINDUCED REACTIONS OF CR(CO)3-COORDINATED 1,3,5-CYCLOHEPTATRIENE - (6+2) CYCLOADDITION WITH AN ALKYNE AND CATALYTIC 1,6-HYDROGENATION


FISCHLER I., GREVELS F., LEITICH J., OZKAR S.

CHEMISCHE BERICHTE-RECUEIL, vol.124, no.12, pp.2857-2861, 1991 (Peer-Reviewed Journal) identifier identifier

  • Publication Type: Article / Article
  • Volume: 124 Issue: 12
  • Publication Date: 1991
  • Doi Number: 10.1002/cber.19911241229
  • Journal Name: CHEMISCHE BERICHTE-RECUEIL
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.2857-2861
  • Keywords: CHROMIUM COMPLEXES, CYCLOHEPTATRIENE, HYDROGENATION OF, PHOTOREACTIONS, PHOTOCATALYSIS, ALKYNES, CYCLOADDITION WITH, METAL-OLEFIN COMPLEXES, PHOTOCHEMICAL-REACTIONS, PHOTOCATALYTIC HYDROGENATION, CONJUGATED DIENES, CHROMIUM, GROUP-6, NORBORNADIENE, SPECTRA

Abstract

Irradiation of Cr(CO)3(eta(6)-1,3,5-cycloheptatriene) (1) in the presence of bis(trimethylsilyl)ethyne results in [6 + 2] cycloaddition of the alkyne to the cycloheptatriene ligand, yielding Cr(CO)3{eta(4:2)-7,8-bis(trimethylsilyl)bicyclo[4.2.1]nona-2,4,7-triene} (2, 60% yield, PHI = 0.08), which upon oxidative decomposition with Ce(IV) releases the organic cycloadduct, 7,8-bis-(trimethylsilyl)bicyclo[4.2.1]-nona-2,4,7-triene (3). Photocatalytic hydrogenation of 1,3,5-cycloheptatriene in the presence of complex 1 affords 1,3-cycloheptadiene. This process involves 1,6-addition of hydrogen, as demonstrated by using D2.