ИСТИНА

Stereoelectronic factors account for the apparent reversal of donor/acceptor properties of a variety of functional groups by a simple change of their orientation in space. The new reactivity patterns that arise from spatial anisotropy are associated with chameleonic behavior of common organic functionalities [1]. Because donor and acceptor properties are often engraved into our thinking about functional groups by the current educational paradigms, such a stereoelectronic “umpolung” can unlock useful ways of thinking about chemical reactivity and open new doors for reaction design. Isonitriles (isocyanides) combine rich and diverse reactivity with an intriguing dichotomy of electronic properties. In particular, in radical addition to triple nitrogen-carbon bond the substrates demonstrate that they behave as stereoelectronic chameleons [2]. Unlike reactions with alkenes and alkynes, radical addition to isonitriles proceeds in 1,1-addition-manner, which means we deal here with unique non-Markovnikov case. Addition of alkyl, aryl, heteroatom-substituted and heteroatom-centered radicals reveals a number of electronic, supramolecular, and conformational effects potentially useful for the practical control of isonitrile-mediated radical cascade transformations. In addition to polarity and low steric hindrance, radical attack at the relatively strong -bond of isonitriles is assisted by chameleonic supramolecular interactions of the radical center with both the isonitrile π*-system and carbon’s lone pair. These interactions are yet another manifestation of supramolecular control of radical chemistry. We are looking forward to new examples of stereoelectronic chameleons in control of structure and reactivity. References [1] Vatsadze, S.; Loginova, Y.; Gomes, G.; Alabugin, I. Chem. Eur. J., 2017, 23(14), 3225. [2] Gomes, G.; Loginova, Y.; Vatsadze, S.; Alabugin, I. JACS, 2018, 140(43), 14272.