Larry Smith

Sequential multistep reactions catalyzed by polymer-anchored homogeneous catalysts

Abstract : The first examples of sequential miltistep organic reactions carried out over polymer-anchored homogeneous catalysts are reported where two such catalysts are bound to the same crosslinked polymer. Also, sequential catalytic reactions where two catalysts, each anchored to a separate resin, are mixed together in the same reactor were conducted. Sequential cyclooligomerization of butadiene to 4-vinylcyclohexene, (Z,Z)-1,5-cyclooctadiene, and (E,E,E)-1,5,9-cyclododecatriene, followed by hydrogenation to ethylcyclohexane, cyclooctane, and cyclododecane, was accomplished using a single styrene-divinylbenzene resin to which (PPh3)2Ni(CO)2 and (PPh3)3RhCl had been anchored. The same reaction sequence was effected by a mixture of two resins to which (PPh3)2Ni(CO)2 and (PPh3)RhCl were individually attached.

The reaction of dimethylketen with some acid halides

The addition of several acid halides to dimethylketen to produce β-keto-acid halides is described. A correlation exists between the reactivity of the acid halide and the pKa of the acid from which the acid from which the acid halide is derived. Dimethylketen is more reactive than diphenyl- and phenylethyl-keten. This is not a general reaction of keten and acid halides.