Photocatalytic Hydrodichloromethylation of Unactivated Alkenes with Chloroform
Dawei Gong1, Caiyu Gao1, Yanlin Zhang2
1Key Laboratory of Preparation and Application of Environmental Friendly Materials, Ministry of Education, College of Chemistry, Jilin Normal University, Changchun 130103, People's Republic of China.
Abstract:
A visible-light-induced method for the hydrodichloromethylation of unactivated alkenes using chloroform (CHCl3) was developed, employing pyridine·BH3 as the halogen atom transfer (XAT) reagent. The strategy showed a broad functional group tolerance, and 29 examples of unactivated alkenes, including complex natural products or drug derivatives, have been established with good yields. Mechanistic studies indicated that CHCl3 serves as both the source of a dichloromethyl radical and a hydrogen atom transfer (HAT) reagent, and the borane short-chain reaction process was involved in this system. This method represents a novel approach for hydrodichloromethylation of unactivated alkenes without using an additional HAT reagent.
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