A Conjugate Addition Approach to Diazo‐Containing Scaffolds with β Quaternary Centers

Design of 'tolerant and hard' superhydrophobic coatings to freeze physical deformation

While the development of mechanically durable and abrasion tolerant superhydrophobicity on a rigid substrates itself remains a highly challenging task, the design of superhydrophobic coatings that can restrict both the tensile and compressive deformations of soft and deformable substrates is unprecedented-and such an approach would be of potential interest in various applied and fundamental contexts. In this communication, a reaction mixture was developed following a simple 1,4-conjugate addition reaction between selected small molecules and appropriate crosslinkers for achieving 'tolerant and hard' superhydrophobicity-which is not just capable of surviving under severe conditions-but also restricts both the tensile and compressive deformations of the selected soft substrates. The compressive and tensile moduli of the selected soft substrates increased by 2.2 × 10⁴% and 1.8 × 10⁴%, respectively, after the deposition of the appropriate reaction mixtures. Moreover, the integration of the crosslinkers in the reaction mixture provided a facile basis to resist the physical erosion/rupture of the selected soft substrates under severe abrasive conditions. Thus, a simple and elegant chemical approach not only controlled the mechanical properties of the porous and fibrous soft substrates under ambient conditions-but also provided highly tolerant superhydrophobicity-which likely leads to various outdoor applications.

β-Diazocarbonyl Compounds: Synthesis and their Rh(II)-Catalyzed 1,3 C-H Insertions

Herein, we describe the first electrophilic diazomethylation of ketone silyl enol ethers with diazomethyl-substituted hypervalent iodine reagents that gives access to unusual β-diazocarbonyl compounds. The potential of this unexplored class of diazo compounds for the development of new reactions was demonstrated by the discovery of a rare Rh-catalyzed intramolecular 1,3 C-H carbene insertion that led to complex cyclopropanes with excellent stereocontrol.