Sayes Morgane, Benoit Guillaume, Charette André B
Faculty of Arts and Sciences, Department of Chemistry, Université de Montreal, P.O. Box 6128 Station Downtown, Montreal, Quebec, H3C 3J7, Canada.
Angew Chem Int Ed Engl. 2018 Oct 8;57(41):13514-13518. doi: 10.1002/anie.201807347. Epub 2018 Sep 12.
Herein, we report a user-friendly and metal-free UV-A light mediated borocyclopropanation of styrenes using continuous flow technology. A broad range of styrene derivatives can be cyclopropanated in good yields within 1 h residence time to produce highly valuable cyclopropylboronate esters with modest to good diastereoselectivities. The reaction is also applicable to α-substituted styrenes. Mechanistic studies support a photoredox process during which xanthone, a well-known organic photosensitizer, can easily reach a photoexcited state that is available for both an oxidative and a reductive quenching.
在此，我们报道了一种使用连续流技术，以用户友好且无金属的方式通过紫外-A光介导的苯乙烯硼环丙烷化反应。在1小时的停留时间内，多种苯乙烯衍生物可以以良好的产率进行环丙烷化反应，生成具有适度至良好非对映选择性的高价值环丙基硼酸酯。该反应也适用于α-取代的苯乙烯。机理研究支持了一种光氧化还原过程，在此过程中，一种著名的有机光敏剂呫吨酮可以很容易地达到光激发态，该光激发态可用于氧化猝灭和还原猝灭。
