5084-80-0Relevant academic research and scientific papers
A new polymorph of tri(p-tolyl)boroxine
Haberecht, Monika C.,Bolte, Michael,Wagner, Matthias,Lerner, Hans-Wolfram
, p. 657 - 665 (2005)
A new orthorhombic polymorph of tri(p-tolyl)boroxine (Pmn21) with relatively short intermolecular B-O distances of 3.321 A was crystallized from CDCl3 at ambient temperature. The crystal structure of the orthorhombic polymorph of tri
Direct Imide Formation from Thiophene Dicarboxylic Acids Gives Expanded Side-Chain Selection in Thienopyrrolediones
Wolfe, Rylan M. W.,Reynolds, John R.
, p. 996 - 999 (2017)
The synthesis of thienopyrroledione (TPD) has been updated to reduce the number of synthetic steps, remove hazardous and toxic reagents, reduce the amount of byproduct waste, and reduce the use of solvents when unnecessary. Diverse functionalization is possible, introducing 16 examples in yields from 34% to 95%. This reaction scheme was shown to be general for thiophene imides, and a more thorough exploration into side chain engineering is presented with TPD acceptors often used in organic electronic applications.
Synthesis of borophosphonate cage compounds: Influence of substituent and concentration effects on product distribution in condensation reactions of aryl phosphonic acids and boronic acids
Liu, Qian,Contrella, Nathan D.,Filatov, Alexander S.,Jordan, Richard F.
, p. 254 - 262 (2015)
Aryl borophosphonate cage compounds [ArPO3BAr′]n with n = 4 or 6 were synthesized by condensation reactions of ArP(O)(OH)2 and Ar′B(OH)2. (3,5-tBu2-Ph)P(O)(OH)2 (1) reacts with a
Nickel- and Palladium-Catalyzed Cross-Coupling Reactions of Organostibines with Organoboronic Acids
Zhang, Dejiang,Le, Liyuan,Qiu, Renhua,Wong, Wai-Yeung,Kambe, Nobuaki
supporting information, p. 3104 - 3114 (2020/12/11)
A strategy for the formation of antimony-carbon bond was developed by nickel-catalyzed cross-coupling of halostibines. This method has been applied to the synthesis of various triaryl- and diarylalkylstibines from the corresponding cyclic and acyclic halostibines. This protocol showed a wide substrate scope (72 examples) and was compatible to a wide range of functional groups such as aldehyde, ketone, alkene, alkyne, haloarenes (F, Cl, Br, I), and heteroarenes. A successful synthesis of arylated stibine 3 a in a scale of 34.77 g demonstrates high synthetic potential of this transformation. The formed stibines (R3Sb) were then used for the palladium-catalyzed carbon–carbon bond forming reaction with aryl boronic acids [R?B(OH)2], giving biaryls with high selectivity, even the structures of two organomoieties (R and R′) are very similar. Plausible catalytic pathways were proposed based on control experiments.
Copper-Catalyzed Asymmetric Arylation of N-Heteroaryl Aldimines: Elementary Step of a 1,4-Insertion
Wu, Chunlin,Qin, Xurong,Moeljadi, Adhitya Mangala Putra,Hirao, Hajime,Zhou, Jianrong Steve
supporting information, p. 2705 - 2709 (2019/02/06)
Copper complexes of monodentate phosphoramidites efficiently promote asymmetric arylation of N-azaaryl aldimines with arylboroxines. DFT calculations and experiments support an elementary step of 1,4-insertion in the reaction pathway, a step in which an aryl-copper species adds directly across four atoms of C=N?C=N in the N-azaaryl aldimines.
Recyclable, Strong, and Highly Malleable Thermosets Based on Boroxine Networks
Ogden, William A.,Guan, Zhibin
supporting information, p. 6217 - 6220 (2018/05/23)
Traditional thermoset materials have favorable material properties but are unable to reprocess and are difficult to recycle. Small molecule boroxines have been shown to undergo a reversible exchange reaction. Herein we employ boroxine as dynamic cross-lin
Kinetics and Mechanism of the Palladium-Catalyzed Oxidative Arylating Carbocyclization of Allenynes
Bartholomeyzik, Teresa,Pendrill, Robert,Lihammar, Richard,Jiang, Tuo,Widmalm, G?ran,B?ckvall, Jan-E.
supporting information, p. 298 - 309 (2018/01/17)
Pd-catalyzed C-C bond-forming reactions under oxidative conditions constitute a class of important and widely used synthetic protocols. This Article describes a mechanistic investigation of the arylating carbocyclization of allenynes using boronic acids and focuses on the correlation between reaction conditions and product selectivity. Isotope effects confirm that either allenic or propargylic C-H activation occurs directly after substrate binding. With an excess of H2O, a triene product is selectively formed via allenic C-H activation. The latter C-H activation was found to be turnover-limiting and the reaction zeroth order in reactants as well as the oxidant. A dominant feature is continuous catalyst activation, which was shown to occur even in the absence of substrate. Smaller amounts of H2O lead to mixtures of triene and vinylallene products, where the latter is formed via propargylic C-H activation. The formation of triene occurs only in the presence of ArB(OH)2. Vinylallene, on the other hand, was shown to be formed by consumption of (ArBO)3 as a first-order reactant. Conditions with sub-stoichiometric BF3·OEt2 gave selectively the vinylallene product, and the reaction is first order in PhB(OH)2. Both C-H activation and transmetalation influence the reaction rate. However, with electron-deficient ArB(OH)2, C-H activation is turnover-limiting. It was difficult to establish the order of transmetalation vs C-H activation with certainty, but the results suggest that BF3·OEt2 promotes an early transmetalation. The catalytically active species were found to be dependent on the reaction conditions, and H2O is a crucial parameter in the control of selectivity.
Palladium(II)-Catalyzed Enantioselective Synthesis of α-(Trifluoromethyl)arylmethylamines
Johnson, Thomas,Luo, Bo,Lautens, Mark
, p. 4923 - 4930 (2016/07/06)
We describe a method for the synthesis of α-(trifluoromethyl)arylmethylamines that consists of the palladium(II)-catalyzed addition of arylboroxines to imines derived from trifluoroacetaldehyde. Palladium acetate is used as a catalyst with electron-neutral or electron-rich arylboroxines, and it was found that addition of an ammonium or silver salt was crucial to promote the reaction of electron-poor boroxines. With (S)-t-Bu-PyOX as the chiral ligand, this method delivers a variety of α-trifluoromethylated amines in 57-91% yield and with greater than 92% ee in most cases.
Rhodium-Catalyzed Asymmetric Arylation/Defluorination of 1-(Trifluoromethyl)alkenes Forming Enantioenriched 1,1-Difluoroalkenes
Huang, Yinhua,Hayashi, Tamio
supporting information, p. 12340 - 12343 (2016/10/07)
The reaction of 1-(trifluoromethyl)alkenes (CF3CH=CHR) with arylboroxines (ArBO)3 in the presence of a chiral diene-rhodium catalyst gave high yields of chiral 1,1-difluoroalkenes (CF2=CHC?HArR) with high enantioselectivity (≥95% ee). The reaction is assumed to proceed through β-fluoride elimination of a β,β,β-trifluoroalkylrhodium intermediate that is generated by arylrhodation of the 1-(trifluoromethyl)alkene.
Asymmetric Synthesis of Triarylmethanes by Rhodium-Catalyzed Enantioselective Arylation of Diarylmethylamines with Arylboroxines
Huang, Yinhua,Hayashi, Tamio
supporting information, p. 7556 - 7559 (2015/07/01)
The reaction of racemic diarylmethylamines, (Ar1Ar2CHNR2), where Ar1 is substituted with a 2-hydroxy group, with arylboroxines (Ar3BO)3 in the presence of a chiral diene-rhodium catalyst gave high yields of chiral triarylmethanes (Ar1Ar2CH?Ar3) with high enantioselectivity (up to 97% ee). The reaction is assumed to proceed through o-quinone methide intermediates which undergo Rh-catalyzed asymmetric 1,4-addition of the arylboron reagents.
