You‐Quan Zou

Visible-light photocatalysis is a rapidly developing and powerful strategy to initiate organic transformations, as it closely adheres to the tenants of green and sustainable chemistry. Generally, most visible-light-induced photochemical reactions occur through single-electron transfer (SET) pathways. Recently, visible-light-induced energy-transfer (EnT) reactions have received considerable attentions from the synthetic community as this strategy provides a distinct reaction pathway, and remarkable achievements have been made in this field. In this Review, we highlight the most recent advances in visible-light-induced EnT reactions.

The [2 + 2] photocycloaddition is undisputedly the most important and most frequently used photochemical reaction. In this review, it is attempted to cover all recent aspects of [2 + 2] photocycloaddition chemistry with an emphasis on synthetically relevant, regio-, and stereoselective reactions. The review aims to comprehensively discuss relevant work, which was done in the field in the last 20 years (i.e., from 1995 to 2015). Organization of the data follows a subdivision according to mechanism and substrate classes. Cu(I) and PET (photoinduced electron transfer) catalysis are treated separately in sections 2 and 4 , whereas the vast majority of photocycloaddition reactions which occur by direct excitation or sensitization are divided within section 3 into individual subsections according to the photochemically excited olefin.

To shed light on: The title reaction allows the generation of a variety of functionalized phenols and analogues using [Ru(bpy)3Cl2]⋅6 H2O as the photocatalyst under very mild reaction conditions. This reaction not only incorporates an oxygen atom from molecular oxygen directly into the product, but also expands the application of visible-light photocatalysis. bpy=bipyridine. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

A ray of sunshine: The title reaction sequence using ethyl 2-(3,4-dihydroisoquinolin-2(1H)-yl)acetates with a series of electron-deficient alkenes and alkynes provides rapid and efficient access to pyrrolo[2,1-a]isoquinolines (see scheme; bpy=2,2′-bipyridine, EWG=electron-withdrawing group). The reaction offers a strategically new protocol for the direct and efficient construction of the core structure of naturally occurring lamellarin alkaloids.