Empowering boronic acids as hydroxyl synthons for aryne induced three-component coupling reactions

Abstract

Boronic acids have become one of the most prevalent classes of reagents in modern organic synthesis, displaying various reactivity profile via C-B bond cleavage. Herein, we describe the utilization of...

When Aryne Chemistry Meets Organosulfur Compounds

“…17 Despite the enormous difficulties encountered during the COVID-19 pandemic in China, we successfully executed our idea and presented a proof-of-concept application of a boronic acid as the hydroxy source in three-component ring-opening hydroxylation reactions (Scheme 5). 18 Compared to water and metal hydroxides, this in situ formed B-F complex can convey a unique reactivity paradigm, leading to versatile alcohol products in moderate to good yields. Moreover, a systematic investigation on structure-activity relationships suggested that harnessing the electronic and steric parameters around the boron center of the boronic acid could permit the effective modulation of its reactivity toward B-O bond cleavage, thereby rendering it a tunable…”

Aryne and CO2-based formal [2 + 2 + 2] annulation to access tetrahydroisoquinoline-fused benzoxazinones

“…11 Arynes are highly reactive electrophiles widely used for producing polysubstituted benzene derivatives. 12 Due to their susceptibility to nucleophilic attack, arynes have been used in several multi-component reactions with CO 2 , and secondary/tertiary aromatic amines in reactions with CO 2 and arynes to generate anthranilic acids and esters. 13 Additionally, Yoshida et al reported the successful incorporation of linear imines with arynes and CO 2 , leading to valuable benzoxazinones through a [2 + 2 + 2] annulation process, although their study only focused on linear imines.…”

Selective S-Arylation of Sulfenamides with Arynes: Access to Sulfilimines

“…Because of the discovery of Kobayashi precursors, aryne chemistry has witnessed a renaissance in recent years, leading to the development of numerous novel transformations. , These unique methods feature mild conditions, the absence of transition metals, and operational simplicity, thereby allowing the development of molecular complexity with a high efficacy. Given our long-standing interest in the combination of aryne species with organosulfur compounds, we naturally questioned whether the polarizable aryne with a low-lying LUMO could exhibit sufficient “soft” electrophilic character to pair the reactivity with the “soft” sulfur center of sulfenamides to empower chemoselective S -arylation . Although the tentative pathway was proposed on the basis of insights gained from our previous research, we still anticipated several associated challenges .…”

“…The control experiment using heavy water suggested no incorporation of deuterium into the substrate in the presence of TBAF in THF, which might provide evidence to support the direct S -arylation pathway. On the basis of this finding and the literature, − a tentative mechanism was proposed, as shown in Scheme . First, the nucleophilic addition of sulfenamide to aryne formed in situ led to key sulfonium zwitterion intermediates A .…”