Insights into the Schrock ‘chop-chop’ reaction gained from density functional theory and preparation and structure of W2(μ-PhCCPh)(SC6H4-2-Me)6†
Abstract
Computations employing density functional theory on the reactions between ethyne and the model compounds (HE)3MM(EH)3, where M = Mo and W and E = O and S, predict that the alkyne adducts M2(μ-C2H2)(EH)6 are thermodynamically favored with respect to the metathesis products HC
M(EH)3 except when M = W and E = O; the reaction between (tBuO)3W
CPh and 2-MeC6H4SH (>3 equiv.) yields W2(μ-PhCCPh)(SC6H4-2-Me)6 consistent with expectations based on the calculations.