57774-36-4Relevant academic research and scientific papers
Ligand-free palladium catalyzed Ullmann biaryl synthesis: 'Household' reagents and mild reaction conditions
Gong, Xinchi,Wu, Jie,Meng, Yunge,Zhang, Yulan,Ye, Long-Wu,Zhu, Chunyin
supporting information, p. 995 - 999 (2019/03/12)
A palladium catalysed Ullmann biaryl synthesis has been developed using hydrazine hydrate as the reducing reagent at room temperature. The combination of Pd(OAc)2 and hydrazine hydrate works smoothly for the coupling of both electron-rich and electron-deficient aryl iodides, as well as hetero-aryl iodides, leading to a wide range of biaryls in good to excellent yields. The reaction requires only 1 mol% Pd(OAc)2 and the in situ generated palladium naoparticles are found to be active catalysts.
Nickel-Catalyzed Cyanation of Aryl Chlorides and Triflates Using Butyronitrile: Merging Retro-hydrocyanation with Cross-Coupling
Yu, Peng,Morandi, Bill
, p. 15693 - 15697 (2017/12/02)
We describe a nickel-catalyzed cyanation reaction of aryl (pseudo)halides that employs butyronitrile as a cyanating reagent instead of highly toxic cyanide salts. A dual catalytic cycle merging retro-hydrocyanation and cross-coupling enables the conversion of a broad array of aryl chlorides and aryl/vinyl triflates into their corresponding nitriles. This new reaction provides a strategically distinct approach to the safe preparation of aryl cyanides, which are essential compounds in agrochemistry and medicinal chemistry.
Strongly Directing Substituents in the Radical Arylation of Substituted Benzenes
Hofmann, Josefa,Clark, Timothy,Heinrich, Markus R.
, p. 9785 - 9791 (2016/10/31)
Although general interest in radical arylation reactions has grown rapidly in recent years, poor regioselectivities and the need to use a large excess of the radical-accepting arene have hindered their application to substituted benzenes. We now describe experimental and computational investigations into the substituent effects that lead to regioselective addition based on the recent discovery of anilines as outstanding substrates for radical arylations.
Palladium and copper-catalyzed ligand-free coupling of phenylhydrazines in water
Chauhan, Parul,Ravi, Makthala,Singh, Shikha,Raju, Kanumuri S. R.,Bajpai, Vikas,Kumar, Brijesh,Wahajuddin,Yadav, Prem. P.
, p. 43336 - 43340 (2015/02/19)
An efficient protocol has been developed for the synthesis of biaryls via Pd/Cu catalyzed coupling of phenylhydrazines in water. Homo and cross couplings were successfully achieved in a ligand-free catalytic system, at room temperature with water as sole reaction medium. This journal is
Structure-reactivity relationships in negishi cross-coupling reactions
Dong, Zhi-Bing,Manolikakes, Georg,Shi, Lei,Knochel, Paul,Mayr, Herbert
supporting information; experimental part, p. 248 - 253 (2010/03/30)
Competition experiments have been performed to determine the relative reactivities of substituted bromobenzenes and of different arylzinc reagents in the [Pd(PPh3)4]-catalyzed Negishi cross-coupling reaction in THF at 25 °C. The crosscoupling reactions are accelerated by electron acceptors in the bromobenzenes, the effect of which increases in the order ortho a larger effect than substituent variations in the arylzinc halides (ρ = -0.98).
Palladium-catalyzed reactions of arylindium reagents prepared directly from aryl iodides and indium metal
Papoian, Vardan,Minehan, Thomas
supporting information; experimental part, p. 7376 - 7379 (2009/05/07)
(Chemical Equation Presented) Treatment of aryl iodides with indium metal in the presence of lithium chloride leads to the formation of an organoindium reagent capable of participating in cross-coupling reactions under transition-metal catalysis. Combination with aryl halides in the presence of 5 mol % Cl2Pd(dppf) furnishes biaryl compounds in good yields; similarly, reaction with acyl halides or allylic acetates/carbonates in the presence of 5-10 mol % palladium catalyst leads to arylketones and allylic substitution products, respectively, in moderate yields. The reactions are tolerant of the presence of protic solvents, and ～85% of the indium metal employed can be recovered by reduction of the residual indium salts with zinc(0).
Sequential photostimulated reactions of trimethylstannyl anions with aromatic compounds followed by palladium-catalyzed cross-coupling processes
Corsico, Eduardo F.,Rossi, Roberto A.
, p. 3311 - 3316 (2007/10/03)
The photostimulated reactions of several mono-, di-, and trichloroarenes and aryltrimethylammonium salts with Me3Sn- ions in liquid ammonia gave good yields of stannanes by the SRN1 mechanism. If the chloroarenes are not soluble in liquid ammonia, diglyme is another solvent to perform these reactions. The stannanes thus obtained can be arylated by further reaction with haloarenes through palladium-catalyzed reactions. If the palladium-catalyzed reaction is performed with a chloroiodoarene as substrate, the stannane reacts faster by the C-I bond via chemoselective cross-coupling reaction to give a chloroarene as product, which can be further arylated by a consecutive SRN1-Stille reaction or react with other substrates by another palladium-catalyzed reaction. These sequential reactions can also be performed with substrates with two leaving groups to give products in high yields.
Phase-Transfer-Catalyzed Gomberg-Bachmann Synthesis of Unsymmetrical Biarenes: A Survey of Catalysts and Substrates
Beadle, James R.,Korzeniowsky, Stephen H.,Rosenberg, David E.,Garcia-Slanga, Blanche J.,Gokel, George W.
, p. 1594 - 1603 (2007/10/02)
Two problems have hindered the Gomberg-Bachmann (GB) and Pschorr reactions of arenediazonium cations: the instability of the arenediazonium salts and side reactions.Arenediazonium tetrafluoroborate and hexafluorophosphate salts can be prepared in high yield and purity and can be stored safely.Unfortunately, these salts are insoluble in most nonpolar organic solvents.Crown ether complexation or other phase-transfer (pt) catalytic methodology can ameliorate this situation, and reactions conducted by the approaches outlined herein often afforded coupling or cyclization products in high yield and corresponding purity.The use of crown ethers, quarternary 'onium salts, lipophilic carboxylic acid salts, and even the polar cosolvent acetonitrile increase the utility of the ptGB reaction dramatically.Sixty examples of couplings are reported along with an assessment of selectivities.A number of examples are also presented of phase-transfer-type Pschorr cyclizations.In the latter case, the use of potassium superoxide, KO2, is introduced to suppress indazole formation.
