20469-72-1Relevant academic research and scientific papers
Rhodium-Catalyzed Pyridine N-Oxide Assisted Suzuki-Miyaura Coupling Reaction via C(O)-C Bond Activation
Zhong, Jing,Long, Yang,Yan, Xufei,He, Shiyu,Ye, Runyou,Xiang, Haifeng,Zhou, Xiangge
supporting information, p. 9790 - 9794 (2019/12/24)
A rhodium-catalyzed Suzuki-Miyaura coupling reaction via C(O)-C bond activation to form 2-benzoylpyridine N-oxide derivatives is reported. Both the C(O)-C(sp2) and C(O)-C(sp3) bond could be activated during the reaction with yields up to 92%. The N-oxide moiety could be employed as a traceless directing group, leading to free pyridine ketones.
Nickel-Catalyzed Directed Hydroarylation of Alkynes with Boronic Acids
Hanna, Luke E.,Konev, Mikhail O.,Jarvo, Elizabeth R.
supporting information, p. 184 - 187 (2018/12/05)
A regio- and stereoselective nickel-catalyzed hydroarylation of alkynes using propargylic carbamates as directing groups has been developed. The reaction proceeds under mild reaction conditions using arylboronic acids in the absence of base. A range of heterocycles and functional groups are tolerated under the reaction conditions, providing high yields of trisubstituted alkenes with control of olefin geometry.
Synthesis of β,β-disubstituted indanones via the Pd-catalyzed tandem conjugate addition/cyclization reaction of arylboronic acids with α,β-unsaturated esters
Gao, Ang,Liu, Xiu-Yan,Li, Hao,Ding, Chang-Hua,Hou, Xue-Long
, p. 9988 - 9994 (2018/05/31)
Under Pd catalysis with a newly synthesized electron-deficient heterocycle, 2-(4,5-dihydroimidazol-2-yl)- pyrimidine (as the ligand), the reaction of α,β-unsaturated esters with arylboronic acids afforded a wide range of 3,3-disubstituted indan-1-ones bearing a quaternary carbon in high yields. Mechanistic studies revealed that the reaction involves a tandem conjugate addition/1,4-Pd shift followed by a cyclization.
Anthranilamide: A simple, removable ortho -directing modifier for arylboronic acids serving also as a protecting group in cross-coupling Reactions
Ihara, Hideki,Koyanagi, Masashi,Suginome, Michinori
, p. 2662 - 2665 (2011/06/25)
Anthranilamide (AAM) serves as a bifunctional modifier on the boron atom in catalytic transformations of arylboronic acids. It makes boronyl groups unreactive in Suzuki-Miyaura coupling and promotes Ru-catalyzed ortho-silylation. Suzuki-Miyaura coupling of AAM-modified bromophenylboronic acids with tolylboronic acid gave 1,1′-biaryl-4-boronic acid bearing AAM on the boron atom, which subsequently underwent Ru-catalyzed ortho-silylation at the 3-position by virtue of the ortho-directing effect of the AAM group.
Single-isomer trisubstituted olefins from a novel reaction of (E)-βchloro-α-iodo-α,β-unsaturated esters and amides
Simard-Mercier, Julie,Jiang, Jojo Liu,Ho, Michael L.,Flynn, Alison B.,Ogilvie, William W.
, p. 5899 - 5906 (2008/12/21)
(Chemical Equation Presented) (E)-β-Chloro-α-iodo-α, β-unsaturated esters are converted to single isomer trisubstituted olefins bearing three different carbon substituents by cross-coupling under reflux. Mechanistic investigations suggest that this process transfers a hydrogen from the boronic acid to the α-position of the substrate and then introduces an aryl group to the β-position of the intermediate template while replacing chloride. The reaction is highly stereoselective, showing preference for the E-isomer. The process proceeds through (E)-β-chloro-α-aryl-α, β-unsaturated esters that are transformed efficiently into the corresponding E-products through stereoselective Suzuki-type reactions giving single isomers. The observed stereo-chemistry is apparently enabled by the intermediacy of a palladium allenoate. The reaction involves a catalytic cycle in which PdII is reduced to Pd0 through the formation of biaryl-coupled products.
Polyelement substituted cyclopentadienes and indenes - Novel ligand precursors for organotransition metal chemistry
Rufanov, Konstantin,Avtomonov, Evgeni,Kazennova, Nadezhda,Kotov, Vasilij,Khvorost, Alexander,Lemenovskii, Dmitry,Lorberth, Joerg
, p. 361 - 373 (2007/10/03)
A series of polyelement substituted cyclopentadienyl and indenyl boranes and arsanes containing Me3Si-, Me3Sn-was synthesised; (C5H4SiMe3)BX2 (2, X = Cl; 3, X = Br) and (C9H6SiMe3)BX2 (4, X = Cl; 5, X = Br) were obtained by Si/B exchange reaction in a low yield when X = Cl and in a moderate yield when X = Br, whereas Flu(SiMe3)2 does not react with BBr3 at all. PhB(C5H4SiMe3)2 (6) and PhB[C5H3(SiMe3)2]2 (7) were synthesised using appropriate thallium cyclopentadienides in high yields, 81% and 99% respectively. More bulky indenyl derivatives TrsB(C9H7)2 (8, Trs = (Me3Si)3C-), PhB(C9H6SiMe3)2 (9), Ph2B(C9H6SiMe3) (10) were prepared by metathesis reactions of lithium indenides with boron halides in high yields. A subsequent transmetallation of C9H6(SnMe3)2 with PhBCl2 followed by addition of ZrCl4 gave (η-5-C9H6SnMe2Cl)2ZrCl2 (11) in the form of one of two possible diastereomers in high yield. C9H6(SiMe3)SnMe3 reacts with BCl3 to give the appropriate bis-indenyl derivative, that was easily converted to the ansa-zirconocene complex [MeB(η5-C9H6)2]ZrCl2 (12). The sterically demanding bis-indenyl ligand 8 underwent direct deprotonation by t-BuLi, affording [TrsB(η5-C9H6)2]ZrCl2 (13) by in situ reaction with Me3SnCl and ZrCl4. Indenylarsanes (C9H7)3As (14), t-BuAs(C9H7)2 (15), C9H7AsMe2 (16) and (C9H6SiMe3)AsMe2 (17) were synthesised by reactions of lithium indenides with asenic halides in good to excellent yields. All these compounds were characterized by analytical and spectroscopic data (NMR, MS). 14 and 15 exist as complex isomeric mixtures with the arsenic atom in the allylic position of the indenyl ring; the crystal structure of a meso form of 15 was determined by X-ray diffraction methods. 17 consists of two isomers with a vinylic (17a) and an allylic (17b) Me3Si substituent. Stannylation of 16 by Me3SnNEt2 led exclusively to the diallylic derivative (C9H6AsMe2)SnMe3 (18) in quantitative yield. The latter was readily converted to a polymeric, half-sandwich indenyl zirconocene [η5-(C9H6AsMe2)ZrCl3]n (19) in high yield. Further reaction of 19 with Cp * Li resulted in the formation of a new arsano substituted bent metallocene complex [η5-(C9H6AsMe2)-η5-(C5Me5)]ZrCl2 (20) in good yield.
