Desymmetrization of Diboron(4) by a Trifluorination B-Masking Strategy: Practical Synthesis of Unsymmetrical Diboron Species.

Herein, we report a straightforward practical and simple method for efficiently synthesizing a BF-containing unsymmetrical diboron salt. This method involves the direct desymmetrization of commercially available diboron(4). This desymmetrization is based on a selective B-masking strategy via nucleophilic trifluorination, providing the elusive diborons bearing a trifluoroborate group.

Stereoselective C-B and C-H Bonds Functionalization of PolyBorylated Alkenes.

Alkenes are fundamental functional groups which feature in various materials and bioactive molecules; however, efficient divergent strategies for their stereodefined synthesis are difficult. In this regard, numerous synthetic methodologies have been developed to construct carbon-carbon bonds with regio- and stereoselectivity, enabling the predictable and efficient synthesis of stereodefined alkenes. In fact, an appealing alternative approach for accessing challenging stereodefined alkene molecular frameworks could involve the sequential selective activation and cross-coupling of strong bonds instead of conventional C-C bond formation.

PolyBorylated Alkenes as Energy-Transfer Reactive Groups: Access to Multi-Borylated Cyclobutanes Combined with Hydrogen Atom Transfer Event.

While polyborylated alkenes are being recognized for their elevated status as highly valuable reagents in modern organic synthesis, allowing efficient access to a diverse array of transformations, including the formation of C-C and C-heteroatom bonds, their potential as energy-transfer reactive groups has remained unexplored. Yet, this potential holds the key to generating elusive polyborylated biradical species, which can be captured by olefins, thereby leading to the construction of new highly-borylated scaffolds. Herein, we report a designed energy-transfer strategy for photosensitized [2+2]-cycloadditions of poly-borylated alkenes with various olefins enabling the regioselective synthesis of diverse poly-borylated cyclobutane motifs, including the 1,1-di-, 1,1,2-tri-, and 1,1,2,2-tetra-borylated cyclobutanes.

Synthesis and Functionalization of Thiophosphonium Salts: A Divergent Approach to Access Thioether, Thioester, and Dithioester Derivatives.

Herein, we report a straightforward practical method for efficiently obtaining a diverse range of thiophosphonium salts. This method involves the direct coupling of commercially available thiols and aldehydes with PhP and TfOH. The setup is simple and carried out in a metal-free manner.

Stereodefined polymetalloid alkenes synthesis via stereoselective boron-masking of polyborylated alkenes.

Polyborylated-alkenes are valuable polymetalloid reagents in modern organic synthesis, providing access to a wide array of transformations, including the construction of multiple C-C and C-heteroatom bonds. However, because they contain similar boryl groups, many times their transformation faces the main challenge in controlling the chemo-, regio- and stereoselectivity. One way to overcome these limitations is by installing different boron groups that can provide an opportunity to tune their reactivity toward better chemo-, regio- and stereoselectivity.