Annulative coupling of vinylboronic esters: aryne-triggered 1,2-metallate rearrangement

Abstract

A stereoselective annulative coupling of vinylboronic ester ate-complex with arynes producing cyclic borinic esters has been developed. An annulation reaction that proceeded through the formation of two C–C bonds and...

4‐Methyltetrahydropyran: A Versatile Alternative Solvent for the Preparation of Chiral BINOL Catalysts and the Asymmetric Alkylation of Aldehydes

“…[10] Despite its promising applications in a series of synthetic transformations, including radical reactions and transition-metal catalyzed processes, [10][11] the use of 4-MeTHP in polar organometallic chemistry is still rather unexplored (Figure 1, A). [10,12] Among the multitude of rearrangement reactions, the anionic ortho-Fries rearrangement (AoF) is a powerful synthetic method to produce relevant functionalized (poly)aromatic compounds. In particular, the AoF offers the possibility to [10][11][12] and b) aim of this work.…”

“…[10,12] Among the multitude of rearrangement reactions, the anionic ortho-Fries rearrangement (AoF) is a powerful synthetic method to produce relevant functionalized (poly)aromatic compounds. In particular, the AoF offers the possibility to [10][11][12] and b) aim of this work.…”

Ring Expansion of Cyclic Boronates via Oxyboration of Arynes

“…6 Recently, Mizoguchi and Sakakura reported the carboboration of arynes with alkenylboronates via 1,2metalate rearrangement. 7 Our group has an ongoing interest in developing new borylation reactions to address significant challenges in synthetic chemistry. 9 In this work, we report the selective B−O bond activation of cyclic boronates, namely, 2-aryl-1,3,2-dioxaborolane derivatives, in the presence of arynes to give the ring-expanded seven-membered borinic acid cyclic esters (Figure 1B), which we discovered serendipitously in the course of our research into the functionalization of 1B).…”

“…Curran and Taniguchi later reported the hydroboration of arynes using N-heterocyclic carbene (NHC)–borane complexes . Recently, Mizoguchi and Sakakura reported the carboboration of arynes with alkenylboronates via 1,2-metalate rearrangement . Despite the very significant progress that has been made in aryne borylation chemistry, there are still no reports of aryne insertion into B–O bonds. − The development of such aryne oxyboration transformations poses a challenge because it requires the selective activation of B–O bonds, which have a relatively high bond dissociation energy (BDE) of 806 kJ/mol compared to other types of boron-based chemical bonds, such as B–B (297 kJ/mol), B–H (330 kJ/mol), and B–C (448 kJ/mol) bonds .…”

“…Arynes are a highly important class of synthetic intermediates that enable the 1,2-difunctionalization of aromatic rings. , These unique chemical species have found widespread use in the construction of functional polycyclic aromatics and structurally complicated bioactive compounds. , In the past decade, the borylative functionalization of arynes has been a particularly active research area, as this strategy allows the production of highly functionalized arylboron compounds that can serve as valuable reagents in organic synthesis (Figure A). − In 2010, Yoshida and co-workers reported the first borylation of arynes . They found that the copper­(I)-catalyzed borylation of arynes using B 2 (pin) 2 resulted in the formation of 1,2-diborylated arenes .…”