Cycloaddition of Coordinated Diazoalkanes to Ethene To Yield 3<i>H</i>-Pyrazole Derivatives
作者:Gabriele Albertin、Stefano Antoniutti、Daniela Baldan、Jesús Castro、Giulia Comparin
DOI:10.1021/om4004016
日期:2013.6.10
Diazoalkane complexes [Ru(eta(5)-C5H5)(N(2)CAr1Ar2)(PPh3)L]BPh4 (1, 2; Ar1 = Ph, Ar2 = p-tolyl; Ar1Ar2 = C12H8; L = P(OMe)(3), P(OEt)(3)) were prepared by allowing compounds RuCl(eta(5)-C5H5)(PPh3)L to react with diazoalkane in ethanol. Treatment of complexes 1 and 2 with ethylene under mild conditions (1 atm, room temperature) led not only to the ethylene complexes [Ru(eta(5)-C5H5)(eta(2)-CH2=CH2)(PPh3)L]BPh4 (5, 6) but also to dipolar (3 + 2) cycloaddition, affording the 3H-pyrazole derivatives [Ru(eta(5)-C5H5)eta(1)-N=NC(Ar1Ar2)CH2CH2}(PPh3)L]BPh4 (3, 4). The propylene complexes [Ru(eta(5)-C5H5)(eta(2)-CH3CH=CH2)(PPh3)L]BPh4 (7, 8) were also prepared. The compounds were characterized by spectroscopy and by X-ray crystal structure determinations of 2a, 3b, and 7.