Divergent Reactivity of a Phosphinidene-Bridged Dimolybdenum Complex Toward 1-Alkynes: P-C, P-H, C-C, and C-H Couplings

作者：Esther Garcia M; Garcia Vivo Daniel^*; Ruiz Miguel A^*; Saez David

来源：Organometallics, 2017, 36(9): 1756-1764.

DOI：10.1021/acs.organomet.7b00121

The ability of complex [Mo2Cp2{mu-P(2,4,6-(C6H2Bu3)-Bu-t)}(CO)(4)] to promote P-C Me and subsequent coupling processes has been analyzed by examining reactions with alkynes. The title compound reacted at room temperature with different terminal alkynes HC CR under visible-UV light irradiation to give, in a selective way, the corresponding phosphapropenediyl derivatives [Mo2Cp2(mu-kappa(1)c:eta(3)c,c,p-CRCHPR*)(CO)(4)] for R groups of varied electron-withdrawing nature, but low to medium size, such as Pr, CO2Me, and p-tol. These products follow from formal insertion of the alkyne into one of the Mo-phosphinidene bonds in the parent compound, with selective P-C coupling to the terminal carbon of bulky Bu-t group, the corresponding photochemical reactions yielded a mixture of the cis and trans isomers of the phosphanyl- and formylalkenyl-bridged complex [Mo2Cp2{mu-kappa(2)c,o:eta(2)c,c-CHC(Bu-t)C(O)H}{mu-P(CH2CMe2)-(C6H2Bu2)-Bu-t}(CO)(2)], which follow from a complex reaction sequence involving an H C(sp(3)) bond cleavage along with different P-C, P-H, C-C, and C-H bond formation steps. Density functional theory calculations were carried out to rationalize the preceding observations and suggested that an isomer of the parent complex displaying a bent terminal phosphinidene ligand might be involved in all the above photochemical reactions.

• 出版日期2017-5-8