Copper-Catalyzed Reagent-Controlled Regioselective Cyanoborylation of Vinylarenes

Fluoroalkylative Ketonization of Malononitrile-Tethered Alkenes via Nickel Electron-Shuttle and Lewis Acid Catalysis

A binary Ni/Eu catalytic system has been developed, which enables an efficient reductive dicarbofunctionalization of unactivated alkenes with alkyl halides and malononitriles. The combination of Ni electron-shuttle catalysis with Eu(OTf)3, a non-redox-type Lewis acid, effectively activates the iminyl radicals, enabling the direct formation of the C(sp3)-C(sp3) bond and β-ketonitrile functionality across a variety of C═C double bonds. This reaction allows for the expedient synthesis of densely functionalized cyclic β-ketonitriles bearing all-carbon quaternary centers.

First-Row d-Block Element-Catalyzed Carbon-Boron Bond Formation and Related Processes

Organoboron reagents represent a unique class of compounds because of their utility in modern synthetic organic chemistry, often affording unprecedented reactivity. The transformation of the carbon-boron bond into a carbon-X (X = C, N, and O) bond in a stereocontrolled fashion has become invaluable in medicinal chemistry, agrochemistry, and natural products chemistry as well as materials science. Over the past decade, first-row d-block transition metals have become increasingly widely used as catalysts for the formation of a carbon-boron bond, a transformation traditionally catalyzed by expensive precious metals. This recent focus on alternative transition metals has enabled growth in fundamental methods in organoboron chemistry. This review surveys the current state-of-the-art in the use of first-row d-block element-based catalysts for the formation of carbon-boron bonds.

Saturated Boronic Acids, Boronates, and Trifluoroborates: An Update on Their Synthetic and Medicinal Chemistry

This review discusses recent advances in the chemistry of saturated boronic acids, boronates, and trifluoroborates. Applications of the title compounds in the design of boron-containing drugs are surveyed, with special emphasis on α-amino boronic derivatives. A general overview of saturated boronic compounds as modern tools to construct C(sp³ )-C and C(sp³ )-heteroatom bonds is given, including recent developments in the Suzuki-Miyaura and Chan-Lam cross-couplings, single-electron-transfer processes including metallo- and organocatalytic photoredox reactions, and transformations of boron "ate" complexes. Finally, an attempt to summarize the current state of the art in the synthesis of saturated boronic acids, boronates, and trifluoroborates is made, with a brief mention of the "classical" methods (transmetallation of organolithium/magnesium reagents with boron species, anti-Markovnikov hydroboration of alkenes, and the modification of alkenyl boron compounds) and a special focus on recent methodologies (boronation of alkyl (pseudo)halides, derivatives of carboxylic acids, alcohols, and primary amines, boronative C-H activation, novel approaches to alkene hydroboration, and 1,2-metallate-type rearrangements).

Three-component reaction of gem-difluorinated cyclopropanes with alkenes and B2pin2 for the synthesis of monofluoroalkenes

Borylative difunctionalization of alkenes has emerged as a powerful approach for synthesizing highly functionalized molecules. Herein, dual Cu/Pd-catalysed borylfluoroallylation of alkenes was smoothly achieved by using gem-difluorinated cyclopropanes and B2pin2, providing the corresponding monofluoroalkene scaffolds in moderate to high yields with excellent stereoselectivity. Moreover, an array of synthetic building blocks can be obtained by downstream transformations.

Copper-Catalyzed Borylative Couplings with C-N Electrophiles

Copper-catalyzed borylative multicomponent reactions (MCRs) involving olefins and C-N electrophiles are a powerful tool to rapidly build up molecular complexity. The products from these reactions contain multiple functionalities, such as amino, cyano and boronate groups, that are ubiquitous in medicinal and process chemistry programs. Copper-catalyzed MCRs are particularly attractive because they use a relatively abundant and non-toxic catalyst to selectively deliver high-value products from simple feedstocks such as olefins. In this Minireview, we explore this rapidly emerging field and survey the borylative union of allenes, dienes, styrenes and other olefins, with imines, nitriles and related C-N electrophiles.

Three-Component Borylallenylation of Alkynes: Access to Densely Boryl-Substituted Ene-allenes

Ene-allenes serve as versatile building blocks in organic synthesis, and the development of their efficient preparation is valuable. Herein the synthesis of boryl-substituted ene-allenes utilizing a Cu/Pd-catalyzed borylallenylation of alkynes with propargylic carbonates and bis(pinacolato)diboron is reported. Densely (tetra-, penta-, and hexa-) substituted ene-allenes were synthesized in acceptable yield with high regio- and stereoselectivity. More important molecule structures can be obtained by subsequent modifications.

The dual-catalyzed boryldifluoroallylation of alkynes: an efficient method for the synthesis of skipped gem-difluorodienes

The Cu/Pd-catalyzed boryldifluoroallylation of alkynes was achieved, providing the skipped gem-difluorodiene scaffolds with high regio- and stereoselectivity. An array of synthetic building blocks can be obtained via further transformations.

Rhodium(iii)-catalyzed aromatic C–H cyanation with dimethylmalononitrile as a cyanating agent

Safe, bench-stable, and commercially available DMMN was used as a cyanating reagent in Rh(iii)-catalyzed aromatic C–H bond direct cyanation in the presence of copper oxide as a promotor.

Cu-catalyzed regioselective borylcyanation of 1,3-dienes

Catalytic regioselective generation of an allyl–Cu complex through Cu–B(pin) (pin = pinacolato) addition to 1,3-dienes followed by reaction with an electrophilic cyanation reagent to afford multifunctional organoboron compounds is presented.