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Abstract The catalytic asymmetric synthesis of axially chiral alkenes remains a daunting challenge due to the lower rotational barrier, especially for longer stereogenic axis (e.g. C-B axis). The asymmetric radical difunctionalization of alkynes represents an efficient strategy for these targets. Key to the success of such transformations lies in aryl-stabilized highly reactive alkenyl radical intermediates, however, it remains an elusive whether a boryl group could play a similar role. Here we report a nickel-catalyzed atroposelective radical relayed reductive coupling reaction of our designed ethynyl-azaborines with simple alkyl and aryl halides through a boron-stabilized vinyl radical intermediate. This transformation enables a straightforward access to the challenging axially chiral alkenylborons bearing a C-B axis in generally high enantioselectivity and excellent stereoselectivity.

Abstract Due to the high reactivity and versatility of benzenesulfonothioates, significant advancements have been made in constructing C-S bonds. However, there are certain limitations in the synthesis of S-thiosulfonates and SS-thiosulfonates, especially when dealing with substantial steric hindrance, which poses a significant challenge. Herein, we present an innovative approach for assembling unsymmetric S-thiosulfonates and unsymmetric SS-thiosulfonates through the integration of dual copper/photoredox catalysis. Moreover, we also realized the one-pot strategy by directly using carboxylic acids as raw materials by in-situ activation of them to access S-thiosulfonates and SS-thiosulfonates without further purification and presynthesis of NHPI esters. The envisaged synthesis and utilization of these reagents are poised to pioneer an innovative pathway for fabricating a versatile spectrum of mono-, di-, and polysulfide compounds. Furthermore, they introduce a class of potent sulfenylating reagents, empowering the synthesis of intricate unsymmetrical disulfides that were previously challenging to access.

Abstract 1,2-Difunctionalization of alkynes offers a straightforward approach to access polysubstituted alkenes. However, simultaneous multi-component cascade transformations including difunctionalization of two alkynes with both syn- and anti-selectivity in one catalyst system is undeveloped and proves to be a significant challenge. Herein, we report a Nickel-catalyzed four-component reaction to access polysubstituted 1,3-dienes using two terminal alkynes, aryl boroxines, and perfluoroalkyl iodides, wherein the reaction forms three new C-C bonds in a single vessel and serve as a modular strategy to access polysubstituted 1,3-dienes with excellent chemoselectivity, good regioselectivity and exclusive stereoselectivity. Control experiments reveal the plausible reaction mechanism and DFT calculations explain the cause for the formation of this unusual four-component reaction. Furthermore, we successfully incorporate two biologically active units into 1,2,3,4-tetrasubstituted 1,3-dienes, which greatly increases the diversity of molecular scaffolds and brings more potential values to medicinal chemistry, the synthetic utility of our protocol is further demonstrated by the late-stage transformations.

Abstract The [1,2]- and [2,3]-Stevens rearrangements are one of the most fascinating chemical bond reorganization strategies in organic chemistry, and they have been demonstrated in a wide range of applications, representing a fundamental reaction tactic for the synthesis of nitrogen compounds in chemical community. However, their applicabilities are limited by the scarcity of efficient, general, and straightforward methods for generating ammonium ylides. Herein, we report a general difluorocarbene-induced tertiary amine-involved [1,2]- and [2,3]-Stevens rearrangements stemmed from in situ generated difluoromethyl ammonium ylides, which allows for the rearrangements of versatile tertiary amines bearing either allyl, benzyl, or propargyl groups, resulting in the corresponding products in one reaction under the same reaction conditions with a general way. Broad substrate scope, simple operation, mild reaction conditions and late-stage modification of natural products highlight the advantages of this strategy, meanwhile, this general rearrangement reaction is believed to bring opportunities for the transformations of nitrogen ylides and the assembly of valuable tertiary amines and amino acids. This will further enrich the reaction repertoire of difluorocarbene species, facilitate the development of reactions involving difluoromethyl ammonium salts, and provide an avenue for the development of this type of rearrangement reactions.

Abstract In recent years, numerous 1,2-R shift (R = aliphatic or aryl) based on tetracoordinate boron species have been well investigated. In the contrary, the corresponding radical migrations, especially 1,2-boryl radical shift for the construction of organoborons is still in its infancy. Given the paucity and significance of such strategies in boron chemistry, it is urgent to develop other efficient and alternative synthetic protocols to enrich these underdeveloped radical 1,2-boron migrations, before their fundamental potential applications could be fully explored at will. Herein, we have demonstrated a visible-light-induced photoredox neutral decarboxylative radical cross-coupling reaction, which undergoes a radical 1,2-boron shift to give a translocated C-radical for further capture of versatile radical acceptors. The mild reaction conditions, good functional-group tolerance, and broad β-boryl NHPI esters scope as well as versatile radical acceptors make this protocol applicable in modification of bioactive molecules. It can be expected that this methodology will be a very useful tool and an alternative strategy for the construction of primary organoborons via a novel radical 1,2-boron shift mode.

Abstract Catalytic dynamic kinetic asymmetric transformation (DyKAT) provides a powerful tool to access chiral stereoisomers from racemic substrates. Such transformation has been widely employed on the construction of central chirality, however, the application in axial chirality remains underexplored because its equilibrium of substrate enantiomers is limited to five-membered metalacyclic intermediate. Here we report a tetracoordinate boron-directed dynamic kinetic asymmetric cross-coupling of racemic, configurationally stable 3-bromo-2,1-azaborines with boronic acid derivatives. A series of challenging C-B axially chiral compounds were prepared with generally good to excellent enantioselectivities. Moreover, this transformation can also be extended to prepare atropisomers bearing adjacent C-B and C-C diaxes with excellent diastereo- and enantio-control. The key to the success relies on the rational design of a reversible tetracoordinate boron intermediate, which is supported by theoretical calculations that dramatically reduces the rotational barrier of the original C-B axis and achieves the goal of DyKAT.

Hemophagocytic lymphohistiocytosis (HLH) is a rare histiocytic disorder characterized by reactive hyperplasia of the mononuclear phagocytic system, which is primarily caused by dysfunction of cytotoxic killer cells and natural killer cells, leading to antigen clearance barriers and the overactivation of the mononuclear phagocytic system due to continuous antigen stimulation. HLH encompasses a group of clinical syndromes marked by the overproduction of inflammatory cytokines. A 68-year-old Chinese man presented with persistent fever, chills, nausea, and vomiting; the patient had no history of any underlying conditions. Laboratory investigations revealed decreased levels of red blood cells, white blood cells, and platelets, along with reduced natural killer cell activity, increased CD25, hyperferritinemia, and the detection of Rickettsia DNA in his blood, meeting the diagnostic criteria of the Histiocyte Society HLH-2004 guidelines. The patient was treated with antibiotics, improving anemia, glucocorticoid therapy, and continuous renal replacement therapy (CRRT), temporarily improving his condition. However, the patient died after 2 years from chronic renal failure caused by septic shock.

Optically enriched 1,1-diboron compounds are significantly underdeveloped because of the paucity of the straightforward synthetic protocols. Herein, the authors report an enantioselective copper-catalyzed cascade double hydroboration of terminal alkynes to access highly enantioenriched gem-diborylalkanes.

Enantioselective catalytic methods for the construction of boron-stereogenic compounds are elusive. In this article, the authors describe a route to these compounds via a copper-catalysed desymmetric B-H insertion on 2-arylpyridine-boranes with carbenes.

Tetracoordinate boron species are common radical precursors in organic synthesis, but the boron species are discarded as by-products. Herein the authors report a strategy to incorporate both the alkyl moiety and boron species into the eventual products, yielding organoboron compounds.

A pyridinium salt catalyzed radical borylation of benzoyl peroxides is reported herein. A range of benzoyl peroxides having different electronic properties were well compatible in this borylation reaction, delivering various arylboronates in good yields at ambient temperature. The current method features simple operation, additive- and base-free, transition-metal-free and mild conditions.

2-Fluoroindoles are an important structural scaffold in many bioactive or therapeutic agents, but efficient constructions of 2-fluoroindole derivatives are very sparce. Here the authors report an efficient and general strategy for the construction of 2-fluoroindoles in which a wide variety of 2-fluoroindoles were accessed with high efficiency and chemoselectivity.

Unsymmetric monothiooxamides as very special and important scaffolds have been widely existing in natural products and bioactive molecules. However, the efficient construction of such compounds are very rare. Herein, we report a simple and practical strategy to achieve unsymmetric monothiooxalamides via S8-mediated defluorination and vulcanization of amines with bromodifluoroalkylative reagents under mild conditions. And the potential applications of such compounds as ligands has been demonstrated in Cu-catalyzed cross coupling reactions. The fluorinated quinoxalinones, benzooxazinone, α-phenyliminoamides, as well as 2-amidobenzothiazoles are obtained in-situ from unsymmetric monothiooxalamides, in which bromodifluoroalkylative reagents undertake selective triple cleavage. Moreover, we also discover that N-aryl-2-amidobenzothiazoles have aggregation-induced luminescence (AIE) characteristics, which might have great potential in the fields of sensing, imaging, diagnosis and treatment.

Multicomponent reactions enable the rapid construction of diverse molecular scaffolds with modularity and step economy. In this work, the authors report the use of boronic acids as carbon nucleophiles in a Passerini-type three-component coupling reaction towards an expanded inventory of α-hydroxyketones.

Alternative carbene precursors for metal-catalyzed cross coupling may expand the portfolio of methods for C-C bond construction. Here, the authors report a Suzuki−Miyaura coupling of Pd−carbene complexes formed by desulfurization of thioureas or thioamides and affording a broad array of amidinium salts and diaryl ketones.

Summary: The development of C1 synthons to afford the products that add one extra carbon has become an important research theme in the past decade, and significant progress has been achieved with CO2, CO, HCOOH, and others as C1 units. Despite the great advance, the search for new C1 synthons that display unique reactivity, complement to the current C1 sources, and add more value to C1 chemistry is still desirable. Herein, we report a quadruple cleavage of chlorodifluoromethane to yield a C1 source, which was successfully employed in the construction of various N-containing compounds especially with pharmaceutical molecules under mild conditions. This strategy provides a useful method for late-stage modification of pharmaceutical compounds. Four bonds in ClCF2H were orderly cleaved under basic conditions in the absence of transition metals. Preliminary mechanistic studies revealed that (E)-N-phenylformimidoyl fluoride intermediate is involved in this process by in situ 1H NMR studies and control experiments. : Catalysis; Organic Chemistry; Organic Synthesis Subject Areas: Catalysis, Organic Chemistry, Organic Synthesis

A copper-catalyzed oxidative direct formation of amides from nonactivated carboxylic acids and azoles with dioxygen as an activating reagent is reported. The azole amides were produced in good to excellent yields with a broad substrate scope. The mechanistic studies reveal that oxygen plays an essential role in the success of the amidation reactions with copper peroxycarboxylate as the key intermediate. Transamidation occurs smoothly between azole amide and a variety of amines.