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6934024 
Journal Article 
Direct C-H Borylation of Arenes Catalyzed by Saturated Hydride-Boryl-Iridium-POP Complexes: Kinetic Analysis of the Elemental Steps 
Esteruelas, MA; Martinez, A; Olivan, M; Onate, E; , 
2020 
Yes 
Chemistry: A European Journal
ISSN: 0947-6539
EISSN: 1521-3765 
WILEY-V C H VERLAG GMBH 
WEINHEIM 
26 
55 
12632-12644 
English 
32428335 
WOS:000566723700001 
The saturated trihydride IrH3{kappa(3)-P,O,P-[xant(PiPr(2))(2)]} (1; xant(PiPr(2))(2)=9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) activates the B-H bond of two molecules of pinacolborane (HBpin) to give H-2, the hydride-boryl derivatives IrH2(Bpin){kappa(3)-P,O,P-[xant(PiPr(2))(2)]} (2) and IrH(Bpin)(2){kappa(3)-P,O,P-[xant(PiPr(2))(2)]} (3) in a sequential manner. Complex3activates a C-H bond of two molecules of benzene to form PhBpin and regenerates2and1, also in a sequential manner. Thus, complexes1,2, and3define two cycles for the catalytic direct C-H borylation of arenes with HBpin, which have dihydride2as a common intermediate. C-H bond activation of the arenes is the rate-determining step of both cycles, as the C-H oxidative addition to3is faster than to2. The results from a kinetic study of the reactions of1and2with HBpin support a cooperative function of the hydride ligands in the B-H bond activation. The addition of the boron atom of the borane to a hydride facilitates the coordination of the B-H bond through the formation of kappa(1)- and kappa(2)-dihydrideborate intermediates.