Center for Catalysis Research and Innovation and Department of Chemistry, University of Ottawa, Ottawa, Ontario K1N6N5 Canada.
J Am Chem Soc. 2015 Jun 17;137(23):7318-21. doi: 10.1021/jacs.5b04524. Epub 2015 Jun 5.
The diverse applications of acrylate metathesis range from synthesis of high-value α,β-unsaturated esters to depolymerization of unsaturated polymers. Examined here are unexpected side reactions promoted by the important Grubbs catalyst GII. Evidence is presented for attack of PCy3 on the acrylate olefin to generate a reactive carbanion, which participates in multiple pathways, including further Michael addition, proton abstraction, and catalyst deactivation. Related chemistry may be anticipated whenever labile metal-phosphine complexes are used to catalyze reactions of substrates bearing an electron-deficient olefin.
烯丙基易位反应的应用多种多样，包括高附加值的α,β-不饱和酯的合成以及不饱和聚合物的解聚。此处研究了重要的 Grubbs 催化剂 GII 促进的意外副反应。研究结果表明，膦配体 PCy3 进攻丙烯酸酯的烯烃生成了一个反应性碳负离子，该碳负离子可以参与多种途径，包括进一步的迈克尔加成、质子抽提和催化剂失活。当使用不稳定的金属-膦配合物来催化带有缺电子烯烃的底物的反应时，可能会出现相关的化学问题。
