Reducing CO2 to Methanol Using Frustrated Lewis Pairs: On the Mechanism of Phosphine鈥揃orane-Mediated Hydroboration of CO2

详细信息    查看全文

• 作者：Marc-Andr茅 Courtemanche ; Marc-Andr茅 L茅gar茅 ; Laurent Maron ; Fr茅d茅ric-Georges Fontaine
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：July 30, 2014
• 年：2014
• 卷：136
• 期：30
• 页码：10708-10717
• 全文大小：580K
• ISSN：1520-5126

文摘

The full mechanism of the hydroboration of CO₂ by the highly active ambiphilic organocatalyst 1-Bcat-2-PPh₂鈥揅₆H₄ (Bcat = catecholboryl) was determined using computational and experimental methods. The intramolecular Lewis pair was shown to be involved in every step of the stepwise reduction. In contrast to traditional frustrated Lewis pair systems, the lack of steric hindrance around the Lewis basic fragment allows activation of the reducing agent while moderate Lewis acidity/basicity at the active centers promotes catalysis by releasing the reduction products. Simultaneous activation of both the reducing agent and carbon dioxide is the key to efficient catalysis in every reduction step.