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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]

A mixture of B(2,6-F SB 2 sb C SB 6 sb H SB 3 sb ) SB 3 sb and the corresponding tetrabutylammonium borohydride salt effectively isomerizes iminium ion B 38 b to form iminium B 41 b via a sequence of hydride donation to form B 39 b followed by hydride abstraction. The ammonium borohydride then eliminates H SB 2 sb to reform the active B(C SB 6 sb F SB 5 sb ) SB 3 sb catalyst and amine B 72 b . Interestingly, the Lewis acid B(2,6-F SB 2 sb C SB 6 sb H SB 3 sb ) SB 3 sb is significantly less electron-deficient than B(C SB 6 sb F SB 5 sb ) SB 3 sb , which is almost exclusively used in organoborane-mediated hydride abstraction with amines. Keywords: boron; hydride abstraction; amines; iminium; functionalization EN boron hydride abstraction amines iminium functionalization 2117 2128 12 10/31/23 20231127 NES 231127 Graph 1 Introduction Organoboranes are widely used as reagents and building blocks in synthetic chemistry. [Extracted from the article]

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]