24973-49-7Relevant articles and documents
Phosphine-Catalyzed Aryne Oligomerization: Direct Access to α,ω-Bisfunctionalized Oligo(ortho-arylenes)
Bürger, Marcel,Ball, Liam T.,Barber, Thomas,Ehrhardt, Nadine,Jones, Peter G.,Namyslo, Jan C.,Werz, Daniel B.
supporting information, p. 16796 - 16803 (2021/10/20)
A phosphine-catalyzed oligomerization of arynes using selenocyanates was developed. The use of JohnPhos as a bulky phosphine is the key to accessing α,ω-bisfunctionalized oligo(ortho-arylenes) with RSe as the substituent at one terminus and CN as the substituent at the other. The in situ formation of R3PSeR′ cations, serving as sterically encumbered electrophiles, hinders the immediate reaction that affords the 1,2-bisfunctionalization product and instead opens a competitive pathway leading to oligomerization. Various optimized conditions for the predominant formation of dimers, but also for higher oligomers such as trimers and tetramers, were developed. Depending on the electronic properties of the electrophilic reaction partner, even compounds up to octamers were isolated. Optimization experiments revealed that a properly tuned phosphine as catalyst is of crucial importance. Mechanistic studies demonstrated that the cascade starts with the attack of cyanide; aryne insertion into n-mers leading to (n+1)-mers was ruled out.
Nickel-Catalyzed Reversible Functional Group Metathesis between Aryl Nitriles and Aryl Thioethers
Delcaillau, Tristan,Boehm, Philip,Morandi, Bill
supporting information, p. 3723 - 3728 (2021/04/07)
We describe a new functional group metathesis between aryl nitriles and aryl thioethers. The catalytic system nickel/dcype is essential to achieve this fully reversible transformation in good to excellent yields. Furthermore, the cyanide- and thiol-free reaction shows high functional group tolerance and great efficiency for the late-stage derivatization of commercial molecules. Finally, synthetic applications demonstrate its versatility and utility in multistep synthesis.
Electrochemical C-H cyanation of electron-rich (Hetero)arenes
Hayrapetyan, Davit,Rit, Raja K.,Kratz, Markus,Tschulik, Kristina,Goo?en, Lukas J.
supporting information, p. 11288 - 11291 (2018/10/20)
A straightforward method for the electrochemical C-H cyanation of arenes and heteroarenes that proceeds at room temperature in MeOH, with NaCN as the reagent in a simple, open, undivided electrochemical cell is reported. The platinum electrodes are passivated by ad-sorbed cyanide, which allows conversion of an exceptionally broad range of electron-rich substrates all the way down to dialkyl arenes. The cyanide electrolyte can be replenished with HCN, opening opportunities for salt-free industrial C-H cyanation.
Ligand-Promoted Direct C-H Arylation of Simple Arenes: Evidence for a Cooperative Bimetallic Mechanism
Kim, Jaewoon,Hong, Soon Hyeok
, p. 3336 - 3343 (2017/06/09)
A highly efficient catalyst for the direct C-H arylation of simple arenes was developed on the basis of a palladium-diimine complex. The developed catalyst exhibited the highest turnover number reported to date for the direct arylation of benzene due to increased stability provided by the diimine ligand. The reaction was also performed using only 2-3 equiv of simple arenes. Mechanistic studies in combination with kinetic measurements, isotope effect experiments, synthesis of possible intermediates, and stoichiometric reactions suggested that this reaction follows a cooperative bimetallic mechanism.
Direct C-H Cyanation of Arenes via Organic Photoredox Catalysis
McManus, Joshua B.,Nicewicz, David A.
supporting information, p. 2880 - 2883 (2017/03/11)
Methods for the direct C-H functionalization of aromatic compounds are in demand for a variety of applications, including the synthesis of agrochemicals, pharmaceuticals, and materials. Herein, we disclose the construction of aromatic nitriles via direct C-H functionalization using an acridinium photoredox catalyst and trimethylsilyl cyanide under an aerobic atmosphere. The reaction proceeds at room temperature under mild conditions and has proven to be compatible with a variety of electron-donating and -withdrawing groups, halogens, and nitrogen- and oxygen-containing heterocycles, as well as aromatic-containing pharmaceutical agents.
PHOTOREDOX-CATALYZED DIRECT C-H FUNCTIONALIZATION OF ARENES
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Paragraph 00385, (2017/01/31)
The invention generally relates to methods of making substituted arenes via direct C-H amination. More specifically, methods of making para- and ortho-substituted arenes via direct C-H amination are disclosed. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.
Azulene–Naphthalene-Type Rearrangements in Benz[a]azulene and Cyclohepta[b]indole
Wentrup, Curt,Becker, Jürgen
, p. 13835 - 13839 (2016/09/21)
Flash vacuum pyrolysis (FVP) of benz[a]azulene yields phenanthrene and 2-ethynylbiphenyl. FVP of cyclohepta[b]indole similarly yields phenanthridine and 2-cyanobiphenyl. The reversibility of the reactions is demonstrated by FVP of 2-ethynylbiphenyl and 2-isocyanobiphenyl. All the observed reactions are in accord with the norcaradiene–vinylidene mechanism of the azulene–naphthalene rearrangement, whereas other proposed mechanisms are ruled out.
Transition-Metal-Free Cross-Coupling of Aryl Halides with Arylstannanes
He, Qing,Wang, Liwen,Liang, Yong,Zhang, Zunting,Wnuk, Stanislaw F.
, p. 9422 - 9427 (2016/10/17)
Transition-metal-free LiCl-promoted cross-coupling reactions of tetraphenyltin, trichlorophenyl-, dichlorodiphenyl-, and chlorotriphenylstannanes with aryl halides in DMF provided access to biaryls in good to high yields. Up to four phenyl groups were transferred from the organostannanes substrates. The aryls bearing electron-withdrawing groups in either halides or organotin substrates gave coupling products in higher yields. The methodology has been applied for the efficient synthesis of ipriflavones.
Generation of iminyl copper species from α-azido carbonyl compounds and their catalytic C-C bond cleavage under an oxygen atmosphere
Chiba, Shunsuke,Zhang, Line,Ang, Gim Yean,Hui, Benjamin Wei-Qiang
supporting information; experimental part, p. 2052 - 2055 (2010/07/04)
Figure presented A copper-catalyzed reaction of α-azidocarbonyl compounds under an oxygen atmosphere is reported where nitriles are formed via C-C bond cleavage of a transient iminyl copper intermediate. The transformation is carried out by a sequence of denitrogenative formation of iminyl copper species from α-azidocarbonyl compounds and their C-C bond cleavage, where molecular oxygen (1 atm) is a prerequisite to achieve the catalytic process and one of the oxygen atoms of O2 was found to be incorporated into the β-carbon fragment as a carboxylic acid.
Pd(PPh3)4-PEG 400 catalyzed protocol for the atom-efficient stille cross-coupling reaction of organotin with aryl bromides
Zhou, Wen-Jun,Wang, Ke-Hu,Wang, Jin-Xian
supporting information; experimental part, p. 5599 - 5602 (2009/12/03)
(Chemical Equation Presented) Aryl bromides (4 equiv) were coupled efficiently with organotin (1 equiv) in an atom-efficient way using the tetra(triphenylphosphine)palladium/polyethylene glycol 400 (Pd(PPh 3)4/PEG 400) catalytic syst
