Aryl Silicon Nucleophiles in Bismuth Catalysis.

We present a catalytic protocol utilizing bismuth for the synthesis of aromatic fluorinated thiosulfones, showcasing a seminal example of aryl silicon nucleophiles in Bi catalysis. This catalytic process is enabled by a series of Bi-based organometallic transformations, including an unprecedented transmetalation of aryl silicates to Bi(III) complexes and the formal migratory insertion of sulfur dioxide (SO) into the Bi-C bond. The protocol is compatible with a wide range of anionic and neutral Ar-Si compounds, including heterocycles.

Photocatalytic Late-Stage C-H Functionalization.

The emergence of modern photocatalysis, characterized by mildness and selectivity, has significantly spurred innovative late-stage C-H functionalization approaches that make use of low energy photons as a controllable energy source. Compared to traditional late-stage functionalization strategies, photocatalysis paves the way toward complementary and/or previously unattainable regio- and chemoselectivities. Merging the compelling benefits of photocatalysis with the late-stage functionalization workflow offers a potentially unmatched arsenal to tackle drug development campaigns and beyond.

Catalytic defluorinative ketyl-olefin coupling by halogen-atom transfer.

Ketyl-olefin coupling reactions stand as one of the fundamental chemical transformations in synthetic chemistry and have been widely employed in the generation of complex molecular architectures and natural product synthesis. However, catalytic ketyl-olefin coupling, until the recent development of photoredox chemistry and electrosynthesis through single-electron transfer mechanisms, has remained largely undeveloped. Herein, we describe a new approach to achieve catalytic ketyl-olefin coupling reactions by a halogen-atom transfer mechanism, which provides innovative and efficient access to various -difluorohomoallylic alcohols under mild conditions with broad substrate scope.

Deaminative chlorination of aminoheterocycles.

Selective modification of heteroatom-containing aromatic structures is in high demand as it permits rapid evaluation of molecular complexity in advanced intermediates. Inspired by the selectivity of deaminases in nature, herein we present a simple methodology that enables the NH groups in aminoheterocycles to be conceived as masked modification handles. With the aid of a simple pyrylium reagent and a cheap chloride source, C(sp)‒NH can be converted into C(sp)‒Cl bonds.

Chemoselective formation of cyclo-aliphatic and cyclo-olefinic 1,3-diols pressure hydrogenation of potentially biobased platform molecules using Knölker-type catalysts.

The hydrogenative conversions of the biobased platform molecules 4-hydroxycyclopent-2-enone and cyclopentane-1,3-dione to their corresponding 1,3-diols are established using a pre-activated Knölker-type iron catalyst. The catalyst exhibits a high selectivity for ketone reduction, and does not induce dehydration. Moreover, by using different substituents of the ligand, the cis-trans ratio of the products can be affected substantially.

C-H Activation: Toward Sustainability and Applications.

Since the definition of the "12 Principles of Green Chemistry" more than 20 years ago, chemists have become increasingly mindful of the need to conserve natural resources and protect the environment through the judicious choice of synthetic routes and materials. The direct activation and functionalization of C-H bonds, bypassing intermediate functional group installation is, , step and atom economic, but numerous factors still hinder the sustainability of large-scale applications. In this Outlook, we highlight the research areas seeking to overcome the sustainability challenges of C-H activation: the pursuit of abundant metal catalysts, the avoidance of static directing groups, the replacement of metal oxidants, and the introduction of bioderived solvents.