355408-55-8Relevant academic research and scientific papers
Ni-Catalyzed Borylation of Aryl Sulfoxides
Huang, Mingming,Wu, Zhu,Krebs, Johannes,Friedrich, Alexandra,Luo, Xiaoling,Westcott, Stephen A.,Radius, Udo,Marder, Todd B.
supporting information, p. 8149 - 8158 (2021/05/10)
A nickel/N-heterocyclic carbene (NHC) catalytic system has been developed for the borylation of aryl sulfoxides with B2(neop)2 (neop=neopentyl glycolato). A wide range of aryl sulfoxides with different electronic and steric properties were converted into the corresponding arylboronic esters in good yields. The regioselective borylation of unsymmetric diaryl sulfoxides was also feasible leading to borylation of the sterically less encumbered aryl substituent. Competition experiments demonstrated that an electron-deficient aryl moiety reacts preferentially. The origin of the selectivity in the Ni-catalyzed borylation of electronically biased unsymmetrical diaryl sulfoxide lies in the oxidative addition step of the catalytic cycle, as oxidative addition of methoxyphenyl 4-(trifluoromethyl)phenyl sulfoxide to the Ni(0) complex occurs selectively to give the structurally characterized complex trans-[Ni(ICy)2(4-CF3-C6H4){(SO)-4-MeO-C6H4}] 4. For complex 5, the isomer trans-[Ni(ICy)2(C6H5)(OSC6H5)] 5-I was structurally characterized in which the phenyl sulfinyl ligand is bound via the oxygen atom to nickel. In solution, the complex trans-[Ni(ICy)2(C6H5)(OSC6H5)] 5-I is in equilibrium with the S-bonded isomer trans-[Ni(ICy)2(C6H5)(SOC6H5)] 5, as shown by NMR spectroscopy. DFT calculations reveal that these isomers are separated by a mere 0.3 kJ/mol (M06/def2-TZVP-level of theory) and connected via a transition state trans-[Ni(ICy)2(C6H5)(η2-{SO}-C6H5)], which lies only 10.8 kcal/mol above 5.
Selective Monoarylation of Aromatic Ketones and Esters via Cleavage of Aromatic Carbon-Heteroatom Bonds by Trialkylphosphine Ruthenium Catalysts
Kondo, Hikaru,Kochi, Takuya,Kakiuchi, Fumitoshi
supporting information, p. 794 - 797 (2017/03/01)
We report here the ruthenium-catalyzed selective monoarylation of aromatic ketones bearing two ortho carbon-heteroatom (O or N) bonds. Under the newly developed catalyst system consisting of RuHCl(CO)(PiPr3)2, CsF, and sty
Simple base-free Miyaura-type borylation of triarylantimony diacetates with tetra(alkoxo)diborons under aerobic conditions
Yasuike, Shuji,Dong, Yuqiang,Kakusawa, Naoki,Matsumura, Mio,Kurita, Jyoji
, p. 80 - 85 (2014/06/24)
The reaction of triarylantimony diacetates with tetra(alkoxo)diborons in the presence of PdCl2(PPh3)2 (1 mol%) catalyst resulted in the Miyaura-type B-arylation to form arylboronates in moderate to good yields under base-free conditions. In the present reaction, two of the three aryl groups of antimony reagent were transferred to the coupling products when the reaction was carried out under aerobic conditions, although only one of the three aryl group of the antimony reagent was involved under an argon atmosphere. The broad scope of the reaction was demonstrated by using a variety of triarylantimony diacetates with sterically hindered aryl groups and highly reactive p-bromo-functionalized aryl derivatives.
Ruthenium-catalyzed α-(hetero)arylation of saturated cyclic amines: Reaction scope and mechanism
Peschiulli, Aldo,Smout, Veerle,Storr, Thomas E.,Mitchell, Emily A.,Elias, Zdenek,Herrebout, Wouter,Berthelot, Didier,Meerpoel, Lieven,Maes, Bert U. W.
supporting information, p. 10378 - 10387 (2013/09/02)
Transition-metal-catalyzed sp3 C-H activation has emerged as a powerful approach to functionalize saturated cyclic amines. Our group recently disclosed a direct catalytic arylation reaction of piperidines at the α position to the nitrogen atom. 1-(Pyridin-2-yl)piperidine could be smoothly α-arylated if treated with an arylboronic ester in the presence of a catalytic amount of [Ru3(CO)12] and one equivalent of 3-ethyl-3-pentanol. A systematic study on the substrate and reagent scope of this transformation is disclosed in this paper. The effect of substitution on both the piperidine ring and the arylboronic ester has been investigated. Smaller (pyrrolidine) and larger (azepane) saturated ring systems, as well as benzoannulated derivatives, were found to be compatible substrates with the α-arylation protocol. The successful use of a variety of heteroarylboronic esters as coupling partners further proved the power of this direct functionalization method. Mechanistic studies have allowed for a better understanding of the catalytic cycle of this remarkable transformation featuring an unprecedented direct transmetalation on a RuII-H species. Copyright
Copper-catalyzed amination of arylboronates with N,N-dialkylhydroxylamines
Matsuda, Naoki,Hirano, Koji,Satoh, Tetsuya,Miura, Masahiro
supporting information; body text, p. 3642 - 3645 (2012/05/20)
A tolerant coupling: The title reaction has been developed to deliver arylamines (see scheme; Bz=benzoyl, dppbz=1,2-bis(diphenylphosphino)benzene). The catalysis is based on electrophilic, umpolung amination and enables the use of secondary acyclic amines. Various functional groups are tolerated, thus opening up a new substrate class for the Chan-Lam-type coupling.
Lithium aminoborohydrides 17. Palladium catalyzed borylation of aryl iodides, bromides, and triflates with diisopropylaminoborane prepared from lithium diisopropylaminoborohydride
Haddenham, Dustin,Bailey, Christopher L.,Vu, Chau,Nepomuceno, Gabby,Eagon, Scott,Pasumansky, Lubov,Singaram, Bakthan
experimental part, p. 576 - 583 (2011/03/18)
The Alcaraz-Vaultier borylation of aryl halides and triflates is reported utilizing diisopropylaminoborane (BH2N(iPr)2) prepared from the corresponding lithium aminoborohydride (LAB reagent). BH 2N(iPr)2, prepared by reacting lithium diisopropylaminoborohydride with trimethylsilyl chloride, provided the most consistent isolated yields from this reaction. Catalytic amounts of palladium dichloride produced the highest yields from aryl iodides, while catalytic tris(dibenzylideneacetone)dipalladium(chloroform) provided the best yields for aryl bromides and triflates. This route to boronic acids is mild enough to tolerate various functionalities and for the first time employs aryl triflates as substrates for the Alcaraz-Vaultier borylation. In addition, it was found that both boronic acid and ester compounds could be isolated from the reaction mixture utilizing simple work-up procedures. Treatment of the reaction intermediate with an acid/base work-up provided the corresponding boronic acid, while treating the same intermediate with a diol, such as neopentyl glycol, afforded the corresponding boronic ester.
Copper-catalyzed cross-coupling reaction of organoboron compounds with primary alkyl halides and pseudohalides
Yang, Chu-Ting,Zhang, Zhen-Qi,Liu, Yu-Chen,Liu, Lei
supporting information; experimental part, p. 3904 - 3907 (2011/05/15)
Non-activated alkyl electrophiles, including alkyl iodides, bromides, tosylates, mesylates, and even chlorides, underwent copper-catalyzed cross-coupling with aryl boron compounds and alkyl 9-BBN reagents (see scheme; 9-BBN=9-borabicyclo[3.3.1]nonane). The reactions proceed with practically useful reactivities and thus complement palladium- and nickel-catalyzed Suzuki-Miyaura coupling reactions of alkyl halides.
Ni(COD)2/PCy3 catalyzed cross-coupling of aryl and heteroaryl neopentylglycolboronates with aryl and heteroaryl mesylates and sulfamates in THF at room temperature
Leowanawat, Pawaret,Zhang, Na,Resmerita, Ana-Maria,Rosen, Brad M.,Percec, Virgil
experimental part, p. 9946 - 9955 (2012/01/15)
Reaction conditions for the Ni(COD)2/PCy3 catalyzed cross-coupling of aryl neopentylglycolboronates with aryl mesylates were developed. By using optimized reaction conditions, Ni(COD)2/PCy 3 was shown to be a versatile catalyst for the cross-coupling of a diversity of aryl neopentylglycolboronates with aryl and heteroaryl mesylates and sulfamates containing both electron-donating and electron-withdrawing substituents in their para, ortho, and meta positions in THF at room temperature. This Ni-catalyzed cross-coupling of aryl neopentylglycolboronates is also effective for the synthesis of heterobiaryls and biaryls containing electrophilic functionalities sensitive to organolithium and organomagnesium derivatives. In combination with the recently developed Nicatalyzed neopentylglycolborylation, all Ni-catalyzed routes to functional biaryls and heterobiaryls are now easily accessible (Figure presented).
Zero-valent metals accelerate the neopentylglycolborylation of aryl halides catalyzed by NiCl2-based mixed-ligand systems
Leowanawat, Pawaret,Resmerita, Ana-Maria,Moldoveanu, Costel,Liu, Chi,Zhang, Na,Wilson, Daniela A.,Hoang, Lisa M.,Rosen, Brad M.,Percec, Virgil
supporting information; experimental part, p. 7822 - 7828 (2011/02/22)
The highly active mixed-ligand catalytic system NiCl2(dppp)/dppf combined with the reducing effect of zerovalent Zn and of other metals was used to demonstrate a method for the dramatic acceleration of the rate and for the enhancement of the yi
Neopentylglycolborylation of ortho -substituted aryl halides catalyzed by NiCl2-Based mixed-ligand systems
Moldoveanu, Costel,Wilson, Daniela A.,Wilson, Christopher J.,Leowanawat, Pawaret,Resmerita, Ana-Maria,Liu, Chi,Rosen, Brad M.,Percec, Virgil
supporting information; experimental part, p. 5438 - 5452 (2010/11/05)
NiCl2-based mixed-ligand systems were shown to be very effective catalysts for the neopentylglycolborylation of aryl iodides, bromides, and chlorides bearing electron-rich and electron-deficient ortho-substituents. Although NiCl2-based single-ligand catalytic systems were able to mediate neopentylglycolborylation of selected substrates, they were not as effective for all substrates, highlighting the value of the mixed-ligand concept. Optimization of the Ni(II)-catalyzed neopentylglycolborylation of 2-iodoanisole and methyl 2-iodobenzoate demonstrated that, while the role of ligand and coligand in the conversion of Ni(II) precatalyst to Ni(0) active catalyst cannot be ignored, a mixed-ligand complex is likely present throughout the catalytic cycle. In addition, protodeborylation and hydrodehalogenation were demonstrated to be the predominant side reactions of Ni(II)-catalyzed borylation of ortho-substituted aryl halides containing the electron-deficient carboxylate substituents. Ni(II) complexes in the presence of H2O and Ni(0) are responsible for the catalysis of these side reactions.
