Palladium-Catalyzed Borylation of Primary Alkyl Bromides

Abstract

A mild Pd-catalyzed process for the borylation of alkyl bromides has been developed using bis(pinacolato)diboron as a boron source. This process accommodates the use of a wide range of functional groups on the alkyl bromide substrate. Primary bromides react with complete selectivity in the presence of a secondary bromide. The generality of this approach is demonstrated by its extension to the use of alkyl iodides and alkyl tosylates, as well as borylation reactions employing bis(neopentyl glycolato)diboron as the boron source.

Copper(I)‐Catalyzed Enantioconvergent Borylation of Racemic Benzyl Chlorides Enabled by Quadrant‐by‐Quadrant Structure Modification of Chiral Bisphosphine Ligands

“…[1,2] Classical synthetic methods involve transmetalation reactions between organometallic reagents and boron electrophiles. [4][5][6][7] Mechanistic studies on such copper(I)-catalyzed borylation reactions have led to ap lausible catalytic cycle that involves ar adical intermediate.Recently,our group has also reported acopper-(I)-catalyzed borylative radical cyclization by exploiting the reactivity of such radicals (Scheme 1b). [3] These reactions provide alkylboronates directly from alkyl electrophiles (Scheme 1a).…”

“…[3] These reactions provide alkylboronates directly from alkyl electrophiles (Scheme 1a). [4][5][6][7] Mechanistic studies on such copper(I)-catalyzed borylation reactions have led to ap lausible catalytic cycle that involves ar adical intermediate.Recently,our group has also reported acopper-(I)-catalyzed borylative radical cyclization by exploiting the reactivity of such radicals (Scheme 1b). [8] In addition, molecular transformations via achiral radical intermediates with chiral catalysts convergently furnish optically active products from racemic starting materials.…”

Copper(I)‐Catalyzed Enantioconvergent Borylation of Racemic Benzyl Chlorides Enabled by Quadrant‐by‐Quadrant Structure Modification of Chiral Bisphosphine Ligands

“…In 2012, Marder, Liu, and co‐workers, as well as our group reported the first examples of catalytic borylation reactions of alkyl electrophiles using copper(I) catalysts . These reactions provide alkylboronates directly from alkyl electrophiles (Scheme a) . Mechanistic studies on such copper(I)‐catalyzed borylation reactions have led to a plausible catalytic cycle that involves a radical intermediate.…”

Synthesis and Minisci Reactions of Organotrifluoroborato Building Blocks

“…15,16 More precisely, copper(I)-catalyzed reactions were particularly successful in the case of 1,4-additions to unsaturated carbonyl compounds, 17,18 and after the pioneering work on activated electrophiles by Miyaura, 19 the last year has witnessed the emergence of aliphatic borylation of halogenated substrates. Therefore, primary, secondary, and even tertiary alkylboronates have been prepared by Cu-, 20,21 Ni-, 22,23 or Pd-catalysis, 24 providing access to previously problematic targets. 25 Herein, we report the use of this method for the preparation of a variety of organotrifluoroborate building blocks of potential use as synthons in the development of drug-like compounds.…”