Daniel A. Straus

Preparation and reaction of metal ketene complexes of Zr and Ti

This report studies the general reaction mechanism route to unsubstituted and alkyl-substituted ketene complexes of titanium and zirconium. Results indicated that the reaction mechanism described in this report can be used to generate a variety of ketene complexes that show a range of reactivities. Their use of models for catalytic intermediates as well as reagents for organometallic and organic synthesis is under further study.

(α,β-Substituted bis(cyclopentadienyl)titanacyclobutanes and their role in productive metathesis

Abstract The synthesis and reactions of the α,β-disubstituted titanacyclobutanes, cis- and trans-Cp2 , are reported. The cis isomer is the less stable and at room temperature isomerizes to the trans isomer and unidentified products. The cis-α.β-dimethylmetallacycle produces a variety of C1 to C5 hydrocarbons upon thermal decomposition. Evidence for competitive cleavage of the cis-α,β-dimethylmetallacycle to give a titanocene ethylidene or a titanocene methylene is presented. The cis-α,β-dimethyl-metallacycle (as well as Cp2 and has been found to catalyze the metathesis of cis,cis- and trans,trans-2,8-decadiene in low yield with moderate stereospecificity. The mechanism of these olefin metathesis reactions is discussed in terms of the chemistry of the model intermediates, the cis- and trans-α,β-dimethyltitanacycles.

Trityl tetraphenylborate as a reagent in organometallic chemistry

Trityl tetraphenylborate, prepared from trityl triflate and sodium tetraphenylborate, is shown to be a useful hydride and methyl anion abstraction reagent for organometallic compounds. It reacts with (η5-C5Me5)(PMe3)2RuMe to give the fulvene complex [η4-C5Me4CH2)(PMe3)2RuMe]BPh4, and with (η5-C5H5)2ZrMe2 in acetonitrile-d3 to afford the cationic methyl derivative [(η5-C5H5)2ZrMe(NCCD3)]BPh4.