20204-73-3Relevant academic research and scientific papers
A Zwitterionic Palladium(II) Complex as a Precatalyst for Neat-Water-Mediated Cross-Coupling Reactions of Heteroaryl, Benzyl, and Aryl Acid Chlorides with Organoboron Reagents
Ramakrishna, Visannagari,Rani, Morla Jhansi,Reddy, Nareddula Dastagiri
, p. 7238 - 7255 (2018/01/01)
The Suzuki–Miyaura cross-coupling (SMC) reactions of several heteroaryl chlorides, benzyl chlorides, and aryl acid chlorides with (hetero)arylboron reagents have been investigated in the presence of [Pd(HL1)(PPh3)Cl2] (I) [HL1 = 3-[(2,6-diisopropylphenyl)-1-imidazolio]-2-quinoxalinide] as catalyst and K2CO3 as base in neat water. The synthesis of the heterocycle-containing biaryls required the addition of 2 mol-% of a phosphine ligand (PPh3 or X-Phos). A combination of more than 115 substrates were screened and it was found that I is a versatile catalyst that can produce heterocycle-containing biaryls, diarylmethanes, and benzophenones in moderate-to-excellent yields.
One-pot borylation/Suzuki-Miyaura sp2-sp3 cross-coupling
Whitaker, Luke,Harb, Hassan Y.,Pulis, Alexander P.
supporting information, p. 9364 - 9367 (2017/08/23)
We describe the first one-pot borylation/Suzuki-Miyaura sp2-sp3 cross-coupling between readily available aryl (pseudo)halides and activated alkyl chlorides. This method streamlines the synthesis of diaryl methanes, α-aryl carbonyls and allyl aryl compounds, substructures that are commonly found in life changing drug molecules.
Efficient N-heterocyclic carbene nickel pincer complexes catalyzed cross coupling of benzylic ammonium salts with boronic acids
Liu, Xi-Yu,Zhu, Hai-Bo,Shen, Ya-Jing,Jiang, Jian,Tu, Tao
, p. 350 - 353 (2017/01/28)
Pyridine-bridged bis-benzimidazolylidene nickel complexes exhibited very high catalytic activity toward cross coupling of inactive (hetero)aryl benzylic ammonium salts with (hetero)aryl and alkenyl boronic acids under mild reaction conditions. Even at 2 mol% catalyst loading, a wide range of substrates for both coupling partners with different steric and electronic properties were well tolerated.
N-Heterocyclic carbene-palladium(II)-1-methylimidazole complex-catalyzed Suzuki-Miyaura coupling of benzyl carbamates with arylboronic acids
Wang, Xiao-Xia,Luo, Mao-Jun,Lu, Jian-Mei
, p. 11438 - 11444 (2015/12/04)
The Suzuki-Miyaura coupling of benzyl carbamates with arylboronic acids was achieved in an environmentally benign medium. Using water as the sole solvent, such transformation took place very well to give the desired diarylmethane derivatives in good to almost quantitative yields in the presence of a well-defined NHC-Pd(ii)-Im complex under mild conditions. It is worth noting here that this is the first example of benzyl carbamates used in coupling reaction, thus affording a new method for the formation of diarylmethanes by palladium-catalyzed C-O bond activation.
Superacid BF3-H2O promoted benzylation of arenes with benzyl alcohols and acetates initiated by trace water
Zhang, Shuting,Zhang, Xiaohui,Ling, Xuege,He, Chao,Huang, Ruofeng,Pan, Jing,Li, Jiaqiang,Xiong, Yan
, p. 30768 - 30774 (2014/08/05)
A convenient procedure employing simple starting materials benzyl alcohols and acetates as the benzyl donors to assemble a series of diarylalkanes through benzylation of arenes using in situ prepared superacid BF3-H 2O as an efficient promoter has been developed. The beneficial role of water in the reaction has been clarified with combination of control experiments and 11B NMR analysis. This reaction is a self-promoted model, which is triggered by the trace of water and continuously promoted by self released by-product water (or carboxylic acid). A wide range of substrates are investigated and the moderate to excellent yields and the good regioselectivities for secondary benzyl alcohols as well as arenes bearing electron-withdrawing groups have been achieved. As a result, moisture in the reaction system has been utilized as an efficient initiator in all benzylation cases.
The nitromethane initiator of the Friedel-Crafts naphthalene reaction using microwaves
Bratulescu,Le Bigot,Delmas
, p. 3309 - 3313 (2007/10/03)
The alkylation of naphthalene using halogen derivatives may be achieved under very simple conditions by the Friedel-Crafts reaction. The products are obtained by irradiation of the paste containing the reaction mixture and a small quantity of nitromethane to initiate the reaction.
Superacid-Catalyzed Reductive Friedel-Crafts Reaction of Arenes Using Arenecarbaldehyde Acetals
Fukuzawa, Shin-Ichi,Tsuchimoto, Teruhisa,Hiyama, Tamejiro
, p. 151 - 156 (2007/10/03)
Reaction of 2-aryl-1,3-dioxane with arenes in the presence of a catalytic amount of trifluoromethane-sulfonic acid gave the corresponding diarylmethanes in good to excellent yields. The acid-catalyzed Friedel-Crafts benzylation of arenes could altenatively be carried out using arenecarbaldehyde and 1,3-propanediol. The reaction was assumed to proceed through a redox process involving hydride shift from the cyclic acetal moiety to the benzylic carbon. The hydride shift was confirmed by the reaction with 5-ethyl-2-phenyl-4,4,6,6-tetradeuterio-1,3-dioxane, wherein more than 90% deuterium was incorporated into the benzylic carbon of the diphenylmethane. Diphenylmethyl ether Ph2CHOCH2CH2CH2OH also reacted with benzene to afford diphenylmethane under the same reaction conditions, suggesting that the ether should be the plausible intermediate that underwent the hydride shift.
Scandium(III) Triflate-Catalyzed Friedel-Crafts Alkylation Reactions
Tsuchimoto, Teruhisa,Tobita, Kazuo,Hiyama, Tamejiro,Fukuzawa, Shin-Ichi
, p. 6997 - 7005 (2007/10/03)
The Sc(OTf)3-catalyzed Friedel-Crafts alkylation reaction with an alcohol, an arenecarbaldehyde or an arenecarbaldehyde acetal as the alkylating agent affords a diarylmethane or an allylbenzene derivative highly selectively. The salient feature of this reaction is that only a catalytic amount of Sc(OTf)3 can effect the reaction. Furthermore, Sc(OTf)3 is recoverable and reusable after the synthetic reaction. The Sc(OTf)3-catalyzed benzylation using an arenecarbaldehyde and 1,3-propanediol or their acetal affords diarylmethane as a sole product in excellent yields in sharp contrast to the original Friedel-Crafts reaction. Since no reaction occurs in the absence of 1,3-propanediol, the reaction is considered to proceed through a redox process including a hydride shift. The hydride shift mechanism is strongly supported by the experimental evidence. The reaction of benzaldehyde with benzene in the presence of 1,3-propanediol-1,1,3,3,-d4 gives rise to the deuterium incorporation into the benzylic carbon of diphenylmethane. Worthy of note is that 1,3-propanediol acts as the hydride source. Herein, diphenylmethyl 3-hydroxypropyl ether is assumed to be the most likely intermediate. In this reaction, Sc(OTf)3 catalyst effectively promotes initial acetal formation, electrophilic aromatic substitution, and successive intramolecular hydride transfer.
Scandium(III) trifluoromethanesulfonate-catalysed reductive Friedel-Crafts benzylation of aromatic compounds using arenecarbaldehydes and propane-1,3-diol
Tsuchimoto, Teruhisa,Hiyama, Tamejiro,Fukuzawa, Shin-Ichi
, p. 2345 - 2346 (2007/10/03)
Scandium(III) trifluoromethanesulfonate catalyses the Friedel-Crafts benzylation of aromatic compounds with arenecarbaldehydes and propane-1,3-diol to produce, through a clean redox process, diarylmethanes in high to excellent yields.
Intramolecular Addition Reactions of Functionalized Arylcarbenes to Arenes
Guth, Michael,Kirmse, Wolfgang
, p. 606 - 613 (2007/10/02)
carbenes with Ar = phenyl (16), 1-naphthyl (20), and 2-furyl (24) have been generated photolytically from appropriate diazo or tosylhydrazone precursors.Intramolecular addition to the arene prevailed in pentane solution, insertion into ortho C-H bonds of the arene being a minor process.On direct photolysis in methanol, intermolecular O-H insertion predominated over intramolecular addition to phenyl and 1-naphthyl groups (kS OH).The ratio of addition to O-H insertion was not affected by benzophenone sensitization in the case of Ar = Ph, but increased strongly in the case of Ar = 1-naphthyl.These data, implying kT > kTS for 20, constitute the first evidence for the addition of triplet arylcarbenes to arenes.Ar = 2-furyl was found to promote the intramolecular addition of both singlet 24 (kS ca. kOH) and triplet 24 (kT > kTS).The reactivity of arenes toward electrophiles (kS) and the stabilization of diradical intermediates (kT) is thought to account for the observed trends.
