The conversion of CF3-alkenes to gem-difluoroalkenes using reductive cross-coupling strategy has received much attention in recent years, however, the use of green and readily available reducing salt to mediate these reactions remains to be explored. In this work a concise construction of gem-difluoroalkenes, which requires neither a catalyst nor a metal reducing agent, was established. Rongalite, a safe and inexpensive industrial product, was employed as both a radical initiator and reductant. This procedure was compatible with both linear and cyclic diaryliodonium salts, enabling a wide variety of substrates (>70 examples). The utility of this approach was demonstrated through gram-scale synthesis and efficient late-stage functionalizations of anti-inflammatory drugs.

Cathode interlayers (CILs) play an essential role in achieving efficient organic solar cells (OSCs). However, the electronic structure at the electrode/CIL/active layer interfaces and the underlying mechanisms for electron collection remain unclear, which becomes a major obstacle to develop high-performance CILs. Herein, we investigate the relationship of the electron collection abilities of four cross-linked and n-doped CILs (c-NDI:P0, c-NDI:P1, c-NDI:P2, c-NDI:P3) with their electronic structure of space charge region at hetero-junction interface. By accurately calculating the depletion region width according to the barrier height, doping density and permittivi-ty, we put forward that the optimal thickness of CIL should be consistent with the depletion region width to realize the minimum en-ergy loss. As a result, the depletion region width is largely reduced from 13 nm to 0.8 nm at the indium tin oxide (ITO)/c-NDI:P0 in-terface, resulting in a decent PCE of 17.7% for the corresponding inverted OSCs.

L-Hexoses are key components of many biologically relevant natural products and pharmaceuticals. As rare sugars, L-hexoses are not readily obtained from natural sources. Access to L-hexose building blocks from commercially available and inexpensive D-sugars is highly desirable from the viewpoints of organic synthesis and drug discovery. As demonstrated by the convenient preparation of L-glucosyl, L-galactosyl, and L-mannosyl fluorides from readily available β-D-C-glucosyl, β-D-C-mannosyl, and β-D-C-galactosyl derivatives, we describe a novel and efficient approach to the demanding L-glycosyl fluorides. The transformation features the installation of anomeric hydroxymethyl group under mild conditions and head-to-tail inversion of sugar rings through radical decarboxylative fluorination of uronic acids. The power of this protocol is highlighted by the first assembly of a pentasaccharide repeating unit of Pseudomonas ATCC 31554 extracellular polysaccharide (S-88). This synthesis relies on the efficient extension of sugar chain at the sterically hindered hydroxy group and the facile introduction of L-mannosyl unit using L-mannosyl fluoride as glycosylating agent. The methods developed in this work would provide new tools to the arsenal of synthesis of L-sugar building blocks and of assembly of glycans containing L-sugar moieties.