Visible-light-promoted synthesis of gem-dihaloenones. Issue 3 (26th January 2023)

• Record Type: Journal Article
• Authors: Wang, Yu-Bin; Chen, Fei; Li, Min; Bu, Qingqing; Du, Zhihong; Liu, Jichang; Dai, Bin; Liu, Ning
• Is Part Of: Green chemistry. Volume 25:Issue 3(2023)
• Page Start: 1191
• Page End: 1200
• Publication Date: 2023-01-26
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/d2gc03989c
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : The first example of a photocatalyst-free strategy for the photo-promoted synthesis of gem -dihaloenones is developed. Abstract : Visible light-promoted strategies were developed for the synthesis of gem -dihaloenones using alkynes and polyhalomethanes as the starting materials. The methods produce a broad range of gem -dibromoenones and gem -dichloroenones without using photocatalysts or additives, such as bases and oxidants. This is the first example of a photocatalyst-free strategy for the photo-promoted synthesis of gem -dihaloenones. These protocols were compatible with various terminal and internal alkynes and were effective in gram-scale experiments. The mechanistic investigations suggested that the tertiary carbon center radical could be a critical intermediate, undergoing β-scission of the C–O bond to form the methyl radical, followed by hydrogen atom transfer (HAT) to produce methane.