A simple method for the conversion of carboxylic acids to boronic esters via redox-active esters (RAEs) is reported using copper catalysis. The scope of this transformation is broad, and compared with the known protocols available, it represents the most inexpensive, rapid, and operationally simple option. In addition to a full exploration of the scope, a kinetic study was performed to elucidate substrate and reagent concentration dependences.
Visible-Light-Mediated Decarboxylative Radical Additions to Vinyl Boronic Esters: Rapid Access to γ-Amino Boronic Esters
作者:Adam Noble、Riccardo S. Mega、Daniel Pflästerer、Eddie L. Myers、Varinder K. Aggarwal
DOI:10.1002/anie.201712186
日期:2018.2.19
The synthesis of alkyl boronicesters by direct decarboxylative radical addition of carboxylic acids to vinyl boronicesters is described. The reaction proceeds under mild photoredox catalysis and involves an unprecedented single-electron reduction of an α-boryl radical intermediate to the corresponding anion. The reaction is amenable to a diverse range of substrates, including α-amino, α-oxy, and
Copper-Catalyzed Borylation of Cyclic Sulfamidates: Access to Enantiomerically Pure (β-and γ-Aminoalkyl)boronic Esters
作者:Nina Ursinyova、Robin B. Bedford、Timothy Gallagher
DOI:10.1002/ejoc.201501492
日期:2016.2
Abstract Cyclicsulfamidates undergo borylation under copper‐catalyzed conditions using B2pin2 to give enantiomerically (and diasteromerically) defined (aminoalkyl)boronicesters. External iodide is essential, but the intermediacy of simple alkyl iodides has been excluded; N‐sulfated intermediates are key in the borylation sequence. Based on stereochemical studies and trapping experiments, the involvement
An electrochemically promoted decarboxylativeborylation reaction is reported. The reaction proceeds under mild conditions in an undivided cell without use of transition metal- or photo-catalysts. The key feature of the reaction is the compatibility of diboron reagents with the electrochemical conditions. This reaction exhibits broad substrate scope, good functional group tolerability, and easy scalability
Visible‐Light‐Promoted Reaction of
<i>N</i>
‐Hydroxyphthalimide Esters with Vinyl Boronic Pinacol Ester
作者:Petros L. Gkizis、Ierasia Triandafillidi、Naya A. Stini、Charikleia S. Batsika、Christoforos G. Kokotos
DOI:10.1002/ejoc.202300152
日期:——
A light-driven protocol to access alkyl boronic acid pinacol esters from vinyl boronate using N-hydroxyphthalimide esters as the alkyl generator was developed. A good substrate scope was examined, demonstrating good to high yields and excellent functional group tolerance.