Compared with the well-developed carbon-stereogenic chemistry, the construction of boron-stereogenic compounds remains undeveloped and challenging. Herein, the previously elusive catalytic enantioselective construction of boron-stereogenic compounds has been achieved through enantioselective desymmetric B–H bond insertion reaction. The B–H bond insertion reaction of 2-arylpyridine-boranes with versatile diazo compounds under chiral copper catalyst can afford boron-stereogenic compounds with good to excellent enantioselectivity. Moreover, the synthetic utility of this reaction is demonstrated by the scalability and downstream transformations. DFT calculations provide insights into the reaction mechanism and the origin of stereoselectivity.

Contrary to the traditional implementation as a difluoromethyl group and recently disclosed role of C1 synthons in synthetic organic chemistry, difluorocarbene (:CF 2 ) is reported herein to proceed unprecedented atom recombination as both C1 synthon and F1 reagent simultaneously to render valuable 3-fluorinated oxindoles from 2aminoarylketones. The reaction does not require any catalyst and features a broad range of substrate scope with good functional group compatibility and ease of execution. This transformation could be employed to the quickconstructions of certain bioactive molecule derivatives. The mechanistic experiments and DFT calculations indicate that this atom recombination reaction of difluorocarbene for the synthesis of 3-fluorinated oxindoles may involve a rearrangement process of epoxide intermediates.

Alkynes are attractive synthons for organic chemistry. Despite the prevalence of transition-metal-catalyzed Sonogashira reactions, a transition-metal-free version of the arylation of terminal alkynes is elusive. Herein, we report an efficient transition-metal-free Sonogashira-type coupling reaction for the one-pot arylation of alkynes to construct C(sp)−C(sp 2 ) bonds from a tetracoordinate boron intermediate with NIS as a mediator. With its high efficiency, wide substrate range, and good functional group tolerance, this method is further supported by the gram-scale synthesis and subsequent modification of complex molecules.

α-Boryl carbonyl species and α-boryl amino compounds are valuable and important frameworks in organic synthesis. However, the strategies that could merge the two scaffolds into one compound, named 1,1-carbonyl amino alkyl boron, are elusive and underdeveloped. Herein, we present an efficient method that could address this gap and produce 1,1-carbonyl amino alkyl borons from readily accessible indoles via oxidation by m-CPBA or oxone. This reaction features operational simplicity, divergent synthesis, broad substrate scope, and valuable products.