Ph2P(BH3)Li: from ditopicity to dual reactivity |
| |
Authors: | Barozzino Consiglio Gabriella Queval Pierre Harrison-Marchand Anne Mordini Alessandro Lohier Jean-François Delacroix Olivier Gaumont Annie-Claude Gérard Hélène Maddaluno Jacques Oulyadi Hassan |
| |
Institution: | CNRS UMR 6014 & FR 3038, Université de Rouen and INSA de Rouen, 76821 Mont St Aignan Cedex, France. |
| |
Abstract: | A multinuclear NMR study shows that the deprotonation of diphenylphosphine-borane by n-BuLi in THF leads to a disolvated lithium phosphido-borane Ph(2)P(BH(3))Li of which Li(+) is connected to the hydrides on the boron and two THF molecules rather than to the phosphorus. This entity behaves as both a phosphination and a reducing agent, depending on the kinetic or thermodynamic control imposed to the reaction medium. Density functional theory computations show that H(2)P(BH(3))Li exhibits a ditopic character (the lithium cation can be in the vicinity of the hydride or of the phosphorus). It explains its dual reactivity (H- or P-addition), both routes going through somewhat similar six-membered transition states with low activation barriers. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|