Photocatalyzed Dual Strain Release of [1.1.1]Propellane with Diazo Compounds
Jiahao Hu, Xiao‐bing Yuan, Yufei Li, Yufei Li, Xiaoyu Chen, Zaicheng Nie, Mong‐Feng Chiou, Yajun Li, Yajun Li, Hongli Bao
Abstract
In recent years, many methods for the synthesis of bicyclo[1.1.1]pentane (BCP) scaffolds have been successfully established owing to their remarkable potent bioactive properties. These BCP scaffolds are typically derived from the single strain release of [1.1.1]propellane. However, approaches for dual strain release of [1.1.1]propellane remain elusive, despite the potential to create innovative opportunities for useful propellane derivatization. In this report, we present herein an efficient method for photocatalyzed dual strain release of [1.1.1]propellane with diazo compounds. Many diazo compounds, including those derived from natural products, such as (+)-borneol, estrone, vitamin E, L-menthol, metronidazole, and geraniol, can be applied to these transformations. Importantly, this method allows the cleavage and formation of multiple C–C bonds in a photocatalyzed tandem intersystem crossing (ISC)/radical ring-opening/radical–radical recombination process, and the products can be easily transformed into synthetically challenging spiro compounds, such as spiro [2.3] and spiro [3.4] compounds.