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Fluorinated triarylboranes have shown a breadth of reactivity as catalysts for organic transformations, particularly in carbon‐carbon bond forming reactions. Herein we report a facile, metal‐free synthetic route for the addition of 2‐phenylimidazo[1,2‐a]pyridines to α,β‐unsaturated ketones using B(C6F5)3 as a metal‐free catalyst. 25 examples of reactions leading to products in up to 97 % yield are reported. DFT studies show the role of B(C6F5)3 and hydrogen shuttling in the mechanism of this Michael alkylation. [ABSTRACT FROM AUTHOR]

The development of new methods for enantioselective reactions that generate stereogenic centres within molecules are a cornerstone of organic synthesis. Typically, metal catalysts bearing chiral ligands as well as chiral organocatalysts have been employed for the enantioselective synthesis of organic compounds. In this review, we highlight the recent advances in main group catalysis for enantioselective reactions using the p‐block elements (boron, aluminium, phosphorus, bismuth) as a complementary and sustainable approach to generate chiral molecules. Several of these catalysts benefit in terms of high abundance, low toxicity, high selectivity, and excellent reactivity. This minireview summarises the utilisation of chiral p‐block element catalysts for asymmetric reactions to generate value‐added compounds. [ABSTRACT FROM AUTHOR]

This article explores the use of fluorinated triarylborane catalysts to activate diazo compounds in organic synthesis. Traditional metal-catalyzed methods have limitations, but borane catalysis offers a transition-metal-free and environmentally friendly approach. The article discusses the reactivity of diazo compounds with triarylboranes, including the binding sites and mode of N2 release. Various reactions using diazo compounds as a carbene synthon in the presence of borane catalysts are catalogued, including O–H bond insertion, S–H insertion, N-alkylation, C–H functionalization, and synthesis of carbocycles and azides. The authors highlight the potential of borane catalysis to advance organic synthesis and offer new directions in synthetic methodology. [Extracted from the article]

In this paper, we compare the reactivity of a series of triaryl borates B(OArx)3 as catalysts for the hydroboration of alkenes and alkynes. It was observed that commercially available B(OPh)3 performed the poorest, whereas catalysts with o-F atoms appeared to perform much better. [ABSTRACT FROM AUTHOR]

Herein we report the B(3,4,5-F3H2C6)3-catalysed C3-allylation of indoles using allylic esters. 25 examples of C3-allylated products are presented in up to 97% yield. The mechanism for the reaction was explored using detailed Density Functional Theory (DFT) studies. [ABSTRACT FROM AUTHOR]

The enlarged landscape of catalysis lies in the heart of chemistry. As the journey has set a milestone in organic synthesis, its darker side has not entered into the limelight. Studies disclose that the reported reactions by using catalysts were also attainable in the absence of catalysts in many cases. This article presents a literature collection that includes the significance of control experiments in hydrofunctionalization reactions. Systematic analysis reveals that the catalysts are ambiguous and might be unessential in chemical reactions enlisted here. [ABSTRACT FROM AUTHOR]

Introduction of an iodine(III) reagent as visible‐light photocatalyst for chemoselective dithioacetalization has been the limelight of the current methodology. The mechanistic investigations reveal that the reactions proceeded via radical pathway upon light induced hemolytic cleavage of C–I bond of the catalyst. Several dithioacetals were easily accessible at room temperature and environmentally benign condition. [ABSTRACT FROM AUTHOR]

Herein we report the use of N‐iodosuccinimide (NIS) as a bifunctional reagent for a regio‐ and (E)‐selective C(sp2)‐H sulfonylation reaction of styrenes. Styrenes and sulfonyl hydrazides treated with NIS and potassium carbonate in ethanol at 70 °C resulted in (E)‐vinyl sulfones exclusively with good to excellent yields. NIS, plays a dual role to generate sulfonyl radical from sulfonyl hydrazides at an initial stage and finally gives β‐iodosulfone intermediate which was further converted to (E)‐vinyl sulfones. Overall, a sustainable method for mild, metal free, convenient, one pot and direct synthesis of (E)‐vinyl sulfones from styrenes are demonstrated via a C−S coupling reaction. Double trouble: N‐iodosuccinimide (NIS) is introduced as a bifunctional reagent towards development of a direct approach of functionalizing C(sp2)‐H of styrene in a regio‐ and (E)‐selective manner. [ABSTRACT FROM AUTHOR]

Precise control of selective alkene functionalization is a continuing challenge in the chemical community. In this study, we develop a substitution‐controlled regiodivergent thioetherification of di‐ or trisubstituted alkenes using 10 mol % tris(pentafluorophenyl)borane [B(C6F5)3] as a catalyst and N‐thiosuccinimide as a sulfenylating reagent. This metal‐free borane catalyzed C−S bond forming method is utilized for a Csp2−H sulfenylation reaction to synthesize an array of diphenylvinylsulfide derivatives with good to excellent yields (25 examples, up to 91 % yield). Some of the products exhibit aggregation‐induced emission luminogen properties used in organic light‐emitting diodes (OLEDs), chemical sensors, and biological imaging units. Depending upon the starting alkene, Csp3−S sulfenylation products could also be generated regioselectively. A variety of allylic thioethers from α‐alkyl substituted styrenes were isolable in good yields and selectivities (14 examples, up to 67 % yield). The DFT‐supported mechanistic study confirms that the reaction proceeds via a thiiranium ion intermediate, where the regioselectivity and product formation is determined by the alkene substituents which influence the activation barriers and energy profiles. Diphenylvinylsulfide derivatives can also be efficiently transformed into a range of synthetically valuable compounds, including vinyl sulfoxides, vinyl sulfones, and vinyl sulfoximines. [ABSTRACT FROM AUTHOR]