Solvent-controlled formation of η3-butadienyl or η3-allyl group 6 transition metal complexes in water or alcohols

Hodson, Annabelle; Thind, Rupinder; Granville-George, Oliver

Abstract

Preparation of acyl chloride, ester, amide or thioester-substituted η3-butadienyl complexes of the type [MCl(CO)2(η3-CH2C(COXR)CCH2)(L2)] (M=Mo,W; XR=Cl, OR, NHR, SR; L2=1,10-phenanthroline (phen), 2,9-dimethyl-1,10-phenanthroline) from 1,4-dichloro-2-butyne and Ph4P[MCl(CO)3(L2)] in water resulted in improved yields (M=Mo) and recycling of reagents. Whilst analogous reactions in anhydrous methanol to yield either substituted η3-butadienyl (XR=OR) or η3-allyl [MoCl(CO)2(η3-CH2C(CO2R)C(OR)Me)(phen)] were dependent upon the presence of organic bases or ethers, reactions in propanol or butanol gave the η3-butadienyl complexes only. Possible mechanisms are discussed. Halide extraction from ester or amide butadienyl complexes in hydroxylic solvents gave highly reactive cations of the type [Mo(CO)2(η3-butadienyl)(phen)(solvent]+, and carboxylate products were obtained by displacement of metal-bound solvent by glucuronate or hydroxybutyrate ions.
Synthesis of acyl chloride, amide, ester or thioester-substituted η3-butadienyl metal complexes in aqueous solution resulted in improved yields over chlorinated solvents and assisted recycling of reactants. Presence of ethers or bases in these reactions in alcohols resulted in controlled formation of either η3-butadienyl or η3-allyl complexes for methanol only.

• Journal Article Type: Article
• Acceptance Date: Mar 11, 2004
• Online Publication Date: Apr 27, 2004
• Publication Date: Jun 15, 2004
• Deposit Date: Mar 13, 2025
• Print ISSN: 0022-328X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 689
• Issue: 12
• Pages: 2114-2122
• Public URL: https://uwe-repository.worktribe.com/output/13936883