Ph2P(BH3)Li: From Ditopicity to Dual Reactivity
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- 作者：Gabriella Barozzino Consiglio ; Pierre Queval ; Anne Harrison-Marchand ; Alessandro Mordini ; Jean-Fran莽ois Lohier ; Olivier Delacroix ; Annie-Claude Gaumont ; H茅l猫ne G茅rard ; Jacques Maddaluno ; Hassan Oulyadi
- 刊名：Journal of the American Chemical Society
- 出版年：2011
- 出版时间：April 27, 2011
- 年：2011
- 卷：133
- 期：16
- 页码：6472-6480
- 全文大小：1029K
- 年卷期：v.133,no.16(April 27, 2011)
- ISSN：1520-5126
文摘
A multinuclear NMR study shows that the deprotonation of diphenylphosphine-borane by n-BuLi in THF leads to a disolvated lithium phosphido-borane Ph2P(BH3)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 H2P(BH3)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.