Cleavage of Carbon-Carbon σ-Bonds of Four-Membered Rings

This article reviews synthetic transformations involving cleavage of a carbon-carbon bond of a four-membered ring, with a particular focus on the examples reported during the period from 2011 to the end of 2019. Most significant is the progress of catalytic reactions involving oxidative addition of carbon-carbon bonds onto transition metals or beta-carbon elimination of transition metal alkoxides. When they are looked at from synthetic perspectives, they offer unique and efficient methods to build complex natural products and structures that are difficult to construct by conventional methods. On the other hand, beta-scission of radical intermediates has also attracted increasing attention as an alternative elementary step to cleave carbon-carbon bonds. Its site-selectivity is often complementary to that of transition metal-catalyzed reactions. In addition, Lewis acid-mediated and thermally induced ring-opening of cyclobutanone derivatives has garnered renewed attention. On the whole, these examples demonstrate unique synthetic potentials of structurally strained four-membered ring compounds for the construction of organic skeletons.

Automated summary

This article reviews synthetic transformations involving the cleavage of a carbon-carbon bond of a four-membered ring from 2011 to 2019, with a particular focus on progress in catalytic reactions such as oxidative addition and beta-carbon elimination, as well as the increasing attention on beta-scission of radical intermediates. Additionally, Lewis acid-mediated and thermally induced ring-opening of cyclobutanone derivatives have garnered renewed interest, demonstrating the unique synthetic potentials of structurally strained four-membered ring compounds for constructing organic skeletons.