Functional Polythioamides Derived from Thiocarbonyl Fluoride.

Polythioamide is a unique type of sulfur-containing polymer with advanced functionalities. Nonetheless, the elemental sulfur commonly used in their synthesis tends to react readily with unsaturated functional groups, thereby limiting the scope of eligible substrates. Inspired by the highly efficient sulfur-fluoride exchange (SuFEx) polymerization through discrete hubs, we present herein a pioneering and versatile approach to the synthesis of polythioamides from diboronic acids, secondary diamines, and thiocarbonyl fluoride as the central connective hub. Well-defined structures, including previously inaccessible unsaturated substrates, were realized. These newly devised polythioamides can efficiently and selectively bind to metal ions and were applied in precious-metal recovery. Further development resulted in PdII -crosslinked single-chain nanoparticles serving as recyclable homogeneous catalysts, thus demonstrating the vast potential of these unprecedented polythioamides. We anticipate that thiocarbonyl fluoride could emerge as a potent hub for facilitating the intricate synthesis of sulfur-containing polymers.

General Access to N-CF3 Secondary Amines and Their Transformation to N-CF3 Sulfonamides.

The synthesis of N-CF3 compounds through fluorination or trifluoromethylation of N-containing compounds has been extensively investigated. However, general access to N-CF3 compounds simply from N-CF3 secondary amines is hampered by the challenging preparation and instability of these amines, as well as a much lower reactivity due to the strong electron-withdrawing nature and steric bulk of the trifluoromethyl moiety. Herein, we report a general and highly efficient synthesis of N-CF3 secondary amines with excellent isolated yields via the addition of the in situ generated difluoromethyl imine (R-N=CF2 ) intermediates with hydrogen fluoride, which is mildly produced by triethylsilane and silver fluoride. N-CF3 sulfonamides, highly desirable but scarce at present, are easily accessible from these valuable building blocks through an unprecedented route. This study will bring new vitality to the synthesis of N-CF3 compounds.