ISSN:
0009-2940
Keywords:
Carbene ligands
;
Chromium complexes
;
Molybdenum complexes
;
Tungsten complexes
;
Annulation reaction
;
Diels-Alder reaction
;
Oxacyclopentenylidene ligands
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Reactions of Complex Ligands, LXI[1]. - Oxacycloalkenylidene Complexes of Chromium, Molybdenum, and Tungsten: Synthesis, Their Annulation with Alkynes and Diels-Alder Reaction with DienesLithiiated propargylic ether 1 reacts with M(CO)6 (M = Cr, Mo, W) to give the 2-oxacyclic carbene complexes 2-4 containing an α,β-double bond and a cyclic acetal structure which serves as a protected benzoyl group. Reaction of the chromium complex 2 with tolan leads to an acyl hydroquinone derivative 5. The tungsten complex 3 undergoes a [4 + 2] cycloaddition with cyclopentadiene to give two diastereomeric oxatricyclic carbene complexes 6 and 7 with an endo/exo selectivity of 3:1. The stereochemistry of the Diels-Alder reaction is controlled by the configuration of the acetal carbon center.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19951280212
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