The present review offers an overview of the current approaches for the photochemical and photocatalytic generation of reactive intermediates and their application in the formation of carbon–carbon bonds. Valuable synthetic targets are accessible, including arylation processes, formation of both carbo- and heterocycles, alpha- and beta-functionalization of carbonyls, and addition reactions onto double and triple bonds. According to the recent advancements in the field of visible/solar light catalysis, a significant part of the literature reported herein involves radical ions and radicals as key intermediates, with particular attention to the most recent examples. Synthetic application of carbenes, biradicals/radical pairs and carbocations have been also reported.

Carbon-Carbon Bond Forming Reactions via Photogenerated Intermediates.

Photocatalysis for the formation of the C-C bond.

Homogeneous metal-catalysis in organic photochemistry

Publisher Summary This chapter provides an overview of the reactions involving cyclic acetals of aldoses and aldosides. The condensation of a sugar with an aldehyde, a ketone, or a dialkoxyalkane in the presence of a desiccant, with (or without) an acid catalyst, has been routinely used for synthesizing cyclic acetals. Interesting progress has also been made on the studies concerning the synthesis of acetals that deals with the strained ring formed from diequatorial, vicinal diols. The halogenation of cyclic acetals, be it halogenation of the side chain at C-2 of a 1,3-dioxolane or halogenation corresponding to a ring-cleavage or a ring-rearrangement, has probably been one of the most studied reactions in the field of the reactivity of cyclic acetal grouping. Cyclic acetals may now be considered not only as classical protecting groups, but also functional groups. In the near future, further developments concerning the utilization of new reagents, or procedures and probably the discovery of the new aspects of the reactivity of cyclic acetals may be expected.

Robert C. Anderson

Papers

A synthesis of naturally occurring (−) isoavenaciolide

Photoaddition of polyfunctional oxycarbinyl species to conjugated enones: A ready route to versatile γ-functionalized ketones.

The Photoaddition of Aldehydes to Enones: A Direct Route to 1,4-Diketones