作者:Mark L. G. Borst、Rosa E. Bulo、Danièle J. Gibney、Yonathan Alem、Frans J. J. de Kanter、Andreas W. Ehlers、Marius Schakel、Martin Lutz、Anthony L. Spek、Koop Lammertsma
DOI:10.1021/ja054885w
日期:2005.12.1
The synthesis of a variety of benzophosphepine complexes [R = Ph, t-Bu, Me; MLn = W(CO)(5), Mo(CO)(5), Cr(CO)(5), Mn(CO)(2)Cp] by two successive hydrophosphinations of 1,2-diethynylbenzene is discussed in detail. The first hydrophosphination step proceeds at ambient temperature without additional promoters, and subsequent addition of base allows full conversion to benzophosphepines. Novel benzeno-1,4-diphosphinanes were isolated as side products. The benzophosphepine complexes themselves serve as convenient phosphinidene precursors at elevated, substituent-dependent temperatures (> 55 degrees C). Kinetic and computational analyses support the proposal that the phosphepine-phosphanorcaradiene isomerization is the rate-determining step. In the absence of substrate, addition of the transient phosphinidene to another benzophosphepine molecule is observed, and addition to 1,2-diethynylbenzene furnishes a delicate bidentate diphosphirene complex.
Direct Access to <i>cis</i>-1,2-Dihydro-1,2-diphosphetes from Butadiynes and Terminal Phosphinidene Complexes
作者:Ngoc Hoa Tran Huy、Louis Ricard、François Mathey
DOI:10.1021/om970487t
日期:1997.9.1
Transient terminal phosphinidenecomplexes [RP→W(CO)5] (R = Ph, Me, Bz, allyl), as generated from the corresponding 7-phosphanorbornadiene complexes, react with substituted butadiynes to afford the corresponding 3-alkynyl-1,2-dihydro-1,2-diphosphete complexes by insertion of a second phosphinidene unit into the alkynyl-substituted P-C ring bond of the initially formed phosphirene complexes. According