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.
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.