Unilever Centre for Molecular Science Informatics, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
J Am Chem Soc. 2012 Feb 8;134(5):2716-22. doi: 10.1021/ja210200d. Epub 2012 Jan 25.
BINOL-derived phosphoric acids catalyze the asymmetric allylboration of aldehydes. DFT and QM/MM hybrid calculations showed that the reaction proceeds via a transition state involving both a hydrogen-bonding interaction from the catalyst hydroxyl group to the pseudoaxial oxygen of the cyclic boronate and a stabilizing interaction from the phosphoryl oxygen of the catalyst to the formyl hydrogen of the aldehyde. These interactions lower the energy of the transition structure and provide extra rigidity to the system. This mechanistic pathway is consistent with the experimentally observed enantioselectivity except in one case. We have used our model's predictions to guide our own experimental work. The conflict is resolved in favor of our calculations.
BINOL 衍生的磷酸可以催化醛的不对称烯丙基硼化反应。DFT 和 QM/MM 混合计算表明，反应通过涉及催化剂羟基与环状硼酸酯的假轴向氧之间氢键相互作用以及催化剂的磷酸基氧与醛的甲酰基氢之间稳定相互作用的过渡态进行。这些相互作用降低了过渡态的能量，并为系统提供了额外的刚性。这种反应机理与实验观察到的对映选择性一致，但有一个例外。我们使用模型的预测来指导我们自己的实验工作。冲突的结果有利于我们的计算。
