C−H Borylation of arenes has been a subject of great interest recently because of its atom‐economy and the wide applicability of borylated products in value‐added synthesis. A new bis(silylene)cobalt(II) complex bearing a bis(N‐heterocyclic silylene)‐pyridine pincer ligand (SiNSi) has been synthesized and structurally characterized. It enabled the regioselective catalytic C−H borylation of pyridines
C(sp<sup>2</sup>)–H Borylation of Fluorinated Arenes Using an Air-Stable Cobalt Precatalyst: Electronically Enhanced Site Selectivity Enables Synthetic Opportunities
作者:Jennifer V. Obligacion、Máté J. Bezdek、Paul J. Chirik
DOI:10.1021/jacs.6b13346
日期:2017.2.22
Cobalt catalysts with electronically enhanced site selectivity have been developed, as evidenced by the high ortho-to-fluorine selectivity observed in the C(sp2)-H borylation of fluorinated arenes. Both the air-sensitive cobalt(III) dihydride boryl 4-Me-(iPrPNP)Co(H)2BPin (1) and the air-stable cobalt(II) bis(pivalate) 4-Me-(iPrPNP)Co(O2CtBu)2 (2) compounds were effective and exhibited broad functional
Non-metal-catalyzed C–H borylation of arenes represents a sustainable and environment-friendly approach for the functionalization of arenes. Despite its promise as an alternative to traditional transition-metal systems, its substrate scope is generally limited to electron-rich arenes, thus hindering its application in organic synthesis. Herein, we report the development of a borenium-ion catalyst which
A Catalytic Borylation/Dehalogenation Route to <i>o</i>-Fluoro Arylboronates
作者:Chathurika R. K. Jayasundara、Jason M. Unold、Jossian Oppenheimer、Milton R. Smith、Robert E. Maleczka
DOI:10.1021/ol5028738
日期:2014.12.5
A two-step Ir-catalyzed borylation/Pd-catalyzed dehalogenation sequence allows for the net synthesis of fluoroarenes where the boronic ester is ortho to fluorine. Key elements of this approach include the use of a halogen para to the fluorine to block meta Ir-catalyzed borylation and the chemoselective Pd-catalyzed dehalogenation by KF activated polymethylhydrosiloxane (PMHS).