502630-89-9Relevant academic research and scientific papers
One-pot borylation/amination reactions: Syntheses of arylamine boronate esters from halogenated arenes
Holmes, Daniel,Chotana, Ghayoor A.,Maleczka Jr., Robert E.,Smith III, Milton R.
, p. 1407 - 1410 (2006)
A one-pot protocol for converting 1,3- and 1,4-substituted aryl halides to arylamine boronate esters is described. This is achieved by sequential Ir-catalyzed aromatic borylation at the least hindered C-H bond of the aryl halide and subsequent Pd-catalyze
SUBSTITUTED ARYL COMPOUND AND PREPARATION METHOD THEREFOR AND USE THEREOF
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Paragraph 0197-0198; 0199-0200, (2021/11/04)
The present application relates to a substituted aryl compound or a pharmaceutically acceptable salt, a stereoisomer, a polymorph, a solvate, a N-oxide, an isotope-labeled compound, a metabolite or a prodrug thereof, and a preparation method therefor and use thereof, also relates to a pharmaceutical composition containing the compound and a therapeutic use thereof. The compound or a pharmaceutical composition thereof can inhibit the activity of adenosine A2a receptor, and can be used for treating or preventing a disease related to adenosine A2a receptor, especially for treating a tumor.
Direct C?H Borylation of Arenes Catalyzed by Saturated Hydride-Boryl-Iridium-POP Complexes: Kinetic Analysis of the Elemental Steps
Esteruelas, Miguel A.,Martínez, Antonio,Oliván, Montserrat,O?ate, Enrique
supporting information, p. 12632 - 12644 (2020/09/09)
The saturated trihydride IrH3{κ3-P,O,P-[xant(PiPr2)2]} (1; xant(PiPr2)2=9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) activates the B?H bond of two molecules of pinacolborane (HBpin) to give H2, the hydride-boryl derivatives IrH2(Bpin){κ3-P,O,P-[xant(PiPr2)2]} (2) and IrH(Bpin)2{κ3-P,O,P-[xant(PiPr2)2]} (3) in a sequential manner. Complex 3 activates a C?H bond of two molecules of benzene to form PhBpin and regenerates 2 and 1, also in a sequential manner. Thus, complexes 1, 2, and 3 define two cycles for the catalytic direct C?H borylation of arenes with HBpin, which have dihydride 2 as a common intermediate. C?H bond activation of the arenes is the rate-determining step of both cycles, as the C?H oxidative addition to 3 is faster than to 2. The results from a kinetic study of the reactions of 1 and 2 with 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 κ1- and κ2-dihydrideborate intermediates.
High-Turnover Aromatic C-H Borylation Catalyzed by POCOP-Type Pincer Complexes of Iridium
Press, Loren P.,Kosanovich, Alex J.,McCulloch, Billy J.,Ozerov, Oleg V.
supporting information, p. 9487 - 9497 (2016/08/12)
The catalytic C-H borylation of arenes with HBpin (pin = pinacolate) using POCOP-type pincer complexes of Ir has been demonstrated, with turnover numbers exceeding 10 000 in some cases. The selectivity of C-H activation was based on steric preferences and largely mirrored that found in other Ir borylation catalysts. Catalysis in the (POCOP)Ir system depends on the presence of stoichiometric quantities of sacrificial olefin, which is hydrogenated to consume the H2 equivalents generated in the borylation of C-H bonds with HBpin. Smaller olefins such as ethylene or 1-hexene were more advantageous to catalysis than sterically encumbered tert-butylethylene (TBE). Olefin hydroboration is a competing side reaction. The synthesis and isolation of multiple complexes potentially relevant to catalysis permitted examination of several key elementary reactions. These experiments indicate that the C-H activation step in catalysis ostensibly involves oxidative addition of an aromatic C-H bond to the three-coordinate (POCOP)Ir species. The olefin is mechanistically critical to gain access to this 14-electron, monovalent Ir intermediate. C-H activation at Ir(I) here is in contrast to the olefin-free catalysis with state-of-the-art Ir complexes supported by neutral bidentate ligands, where the C-H activating step is understood to involve trivalent Ir-boryl intermediates.
Iridium-Catalyzed Borylation of Primary Benzylic C-H Bonds without a Directing Group: Scope, Mechanism, and Origins of Selectivity
Larsen, Matthew A.,Wilson, Conner V.,Hartwig, John F.
supporting information, p. 8633 - 8643 (2015/07/15)
Primary benzylic boronate esters are useful intermediates in organic synthesis, but these reagents cannot be prepared by hydroboration. The benzylic C-H borylation of methylarenes would be a method to form these products, but such reactions without neat methylarene or a directing group are unknown. We report an approach to divert the borylation of methylarenes from aromatic positions to benzylic positions with a silylborane as reagent and a new iridium catalyst containing an electron-deficient phenanthroline as ligand. This system forms benzylic boronate esters selectively over the corresponding aryl boronate esters. An Ir diboryl monosilyl complex ligated by the phenanthroline was isolated and determined to be the resting state of the catalyst. Mechanistic studies show that this complex is kinetically competent to be an intermediate in the catalytic process. Kinetic studies of benzylic and aryl C-H borylation catalyzed by various Ir complexes show that the rate of aryl C-H borylation decreases with decreasing electron density at the metal center of the Ir catalyst, but that the rate of benzylic C-H borylation is less sensitive to the degree of electron density at the metal center of the Ir catalyst. Kinetic and computational studies suggest that the two borylation reactions respond differently to the degree of electron density at the metal center because they occur with different turnover-limiting steps. The turnover-limiting step in the borylation of aryl C-H bonds is known to be C-H oxidative addition, but the turnover-limiting step of the borylation of benzylic C-H bonds appears to be an isomerization prior to C-B reductive elimination.
Iridium-catalyzed preparation of silylboranes by silane borylation and their use in the catalytic borylation of arenes
Boebel, Timothy A.,Hartwig, John F.
, p. 6013 - 6019 (2009/04/13)
Silylboranes are versatile reagents for transition metal-catalyzed reactions of unsaturated organic molecules. These reagents are typically prepared by the addition of a silyl lithium species to a boron electrophile. However, the need to generate anionic silane reagents limits the scope of silylboranes that can be readily obtained. Here, we describe the synthesis of trialkylsilylboranes by the borylation of silanes catalyzed by iridium complexes. The reaction of trialkylhydrosilanes with B2pin 2 catalyzed by the combination of [Ir(OMe)cod]2 and 4,4′-di-tert-butylbipyridine forms trialkylsilylboronic esters. In addition, we show that these trialkylsilylboranes serve as boron sources for the iridium-catalyzed borylation of aryl C-H bonds. In contrast to diboron reagents, the silylboranes react with methylarenes at both the aryl and methyl C-H bonds.
Synthesis of aminoarylboronic esters and substituted anilines from arenes via catalytic C-H activation/borylation/amination and uses thereof
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Page 7-11, (2010/02/05)
A process is described for synthesizing aminoarylboronic esters of the general formula wherein R, R2, and R3 are each an alkyl, aryl, vinyl, alkoxy, carboxylic esters, amides, or halogen; Ar is any variety of phenyl, naphthyl, anthracyl, heteroaryl; and R1 is alkyl, hydrogen, or aryl. The aminoarylboronic esters are produced via the metal-catalyzed coupling of arylboronic esters of the general formula wherein R and R1 are any non-interfering group and X is chloro, bromo, iodo, triflates, or nonaflates to amines (primary and secondary). In particular, a process is described for the synthesis of the aminoarylboronic esters via a step-wise or tandem process in which one catalytic event is a metal-catalyzed borylation and the other catalytic event is a metal-catalyzed amination.
