443634-31-9Relevant academic research and scientific papers
Reactions of tungsten phosphonium carbyne complexes with aryloxide nucleophiles to form aryloxycarbyne and η2-ketenyl complexes
Stone, Kenneth C.,Jamison, Greg M.,White, Peter S.,Templeton, Joseph L.
, p. 161 - 172 (2002)
Tungsten phosphoranylideneketene complexes of the type Tp′(CO)(p-OC6H4R)W(η2-(C,C) -O=CC-PR′2Ph) (R=NO2, R′=Me (6a); R=NO2, R′=Ph (6b); R=CN, R′=Me (7a); R=CN, R′=Ph (7b); R=Cl, R′=Ph (8b)) have been synthesized from phosphonium carbyne precursors in a reaction that reflects coupling of carbonyl and carbyne ligands. In addition to these products, aryloxycarbyne complexes Tp′(CO)2W≡CO(p-C6H4NO 2) (9a), Tp′(CO)2W≡CO(p-C6H4CN) (9b), and Tp′(CO)2W≡CO(p-C6H4Cl) (9c)) have been prepared via substitution of the phosphonium carbyne phosphine with an aryloxide nucleophile. The product ratio of substitution at the carbyne carbon to carbonyl-carbyne coupling can be tuned by variation of the aryloxide para-substituent. Aryloxy carbyne complexes are the favored products with stronger nucleophiles, while weaker nucleophiles result in a mixture of aryloxy carbyne complexes and η2-ketenyl coupled complexes. Formation of η2-ketenyl complexes is favored for the least nucleophilic aryloxides. Ketenyl complexes 6a and 6b were methylated at the ketenyl oxygen to form cationic alkyne complexes [Tp′(CO)(p-OC6H4NO2)W(η 2-(C,C)-CH3OC≡CPR2Ph)][OTf] (R=Me (10a), R=Ph (10b)). The structures of η2-ketenyl complexes 6a and 7b and the structure of cationic alkyne complex 10a were determined by X-ray crystallography.
