Desymmetrization of diborane via “triflouranation”: Novel synthesis of sp²-sp³ diboranes

Diboranes are extremely useful in the synthesis of various kinds of organic scaffolds, ranging from relatively small molecules like drug candidates, to complex organic compounds. Furthermore, they are ideal candidates for building up of organoborones through the creation of C-B bonds, which is one of the most diverse bond in organic chemistry. However, the methods available for the synthesis of organoborones, somehow, suffers from the challenge associated with its preparation.

Our goal is to significantly progress in the design, reactivity, and transformation of new class of sp²-sp³ diborones compounds, in order to achieve the main aim of this research, namely, the construction of organoborone compounds via novel (photoredox) transformations. In this context, we have developed a synthetically viable protocol, operating under green, and mild conditions based on desymmetrization of diboranes (4) via “trifluorination”, for the synthesis of sp²-sp³ diborons. Having these valuable sp²-sp³ diborons in hand, we would like to introduce them, for the first time, as light-labile substrates for creation of organoborones. This new process is unexplored and has the potential to revolutionize the way organoborones molecules are constructed.

• R. Dewhurst; E. C. Neeve; H. Braunschweig; T. B. Marder Chem., Commun., 2015, 51, 9594