Photocatalytic Difunctionalization of [1.1.1]Propellane

Abstract

The hunt for new molecular structures to improve the efficacy of biologically active molecules is at the forefront of pharmaceutical chemistry. So synthetic chemists have always been busy in the last few decades in synthesizing and testing new molecular frameworks which would work as more efficient bioisosteres of present bioactive functional groups. In this area, bicyclo[1.1.1]pentane (BCP) framework has been identified as a promising candidate. It is being utilized as a bioisostere of aryl, tert-butyl, alkynes, etc. in pharmaceutical chemistry. Now the major precursor of various BCP derivatives is [1.1.1]propellane and functionalization of [1.1.1]propellane has drawn widespread attention of the organic chemist community. Over the past two decades, the use of visible light in organic synthesis has rapidly gained popularity, as it represents one of the most efficient approaches aligned with the principles of green and sustainable chemistry, and several interesting papers covering the photocatalytic difunctionalization of [1.1.1]propellane have also been published in the last decade. This particular field has really attracted the attention of organic chemist community. That is why we decided to compile a review article covering the articles related to difunctionalization of [1.1.1]propellane under photocatalytic conditions. Here in this review, we have categorized and discussed the articles under three categories, namely i) without using any catalyst, ii) using organocatalysts, and iii) using metal catalysts for a deeper understanding of various key aspects of these transformations.