78477-43-7Relevant academic research and scientific papers
Direct (Hetero)arylation of Heteroarenes Catalyzed by Unsymmetrical Pd-PEPPSI-NHC Complexes under Mild Conditions
Song, A-Xiang,Zeng, Xiao-Xiao,Ma, Bei-Bei,Xu, Chang,Liu, Feng-Shou
, p. 3524 - 3534 (2020/10/09)
With the aim of developing a facile and efficient method to access structurally intriguing and valuable functionalized (hetero)aryls, two unsymmetrical Pd-PEPPSI-type NHC complexes (PEPPSI, pyridine-enhanced precatalyst preparation, stabilization, and initiation; NHC, N-heterocyclic carbene) were designed and synthesized to catalyze the direct arylation of heteroarenes with (hetero)aryl bromides. The results demonstrated that the utilization of this "unsymmetrical"strategy led to much higher efficiency in comparison to the commonly used C2-symmetric Pd-PEPPSI-type NHC complexes. Furthermore, a broad range of heteroaromatics and (hetero)aryl bromide partners with a wide variety of functional groups were all amenable to the developed protocol even at as low as 0.05 mol % catalyst loading and under aerobic conditions. More importantly, along with our study, we also found that the present protocol could provide expedient access to the gram-scale synthesis of the muscle relaxant drug dantrolene and conjugated mesopolymers.
Eco-friendly solvents for palladium-catalyzed desulfitative C-H bond arylation of heteroarenes
Hfaiedh, Anoir,Yuan, Kedong,Ben Ammar, Hamed,Ben Hassine, Bechir,Soulé, Jean-Fran?ois,Doucet, Henri
, p. 1794 - 1804 (2015/06/02)
Herein, we report the Pd-catalyzed regioselective direct arylation of heteroarenes in which benzenesulfonyl chlorides are used as coupling partners through a desulfitative cross-coupling that can be performed in diethyl carbonate (DEC) or cyclopentyl methyl ether (CPME) as green and renewable solvents or even in neat conditions instead of dioxane or dimethylacetamide (DMA). Under these solvent conditions, the reaction proceeds with a wide range of heteroarenes. C2- or C5-arylated products were obtained with furan and pyrrole derivatives. Benzofuran was also arylated regioselectively at the C2-position, whereas the reaction proceeds selectively at the C3- or C4-positions if thiophenes and benzothiophenes are used. Moreover, in some cases, especially with 1-methylindole, solvent-free conditions afforded better regioselectivities and/or yields than the reaction performed in the presence of solvents.
AgONO-Assisted Direct C-H Arylation of Heteroarenes with Anilines
Gowrisankar, Saravanan,Seayad, Jayasree
supporting information, p. 12754 - 12758 (2015/03/30)
A novel copper-catalyzed C-H arylation of heteroarenes with anilines by an in situ diazonium reaction is established by using silver nitrite (AgONO) as an unconventional nitrosating reagent under acid-free conditions. It provides a complementary approach for the C-H arylation of electron-rich heteroarenes with aromatic amines affording a variety of heterobiaryls in moderate to good yields.
Synthesis of furans, pyrroles and pyridazines by a ruthenium-catalysed isomerisation of alkynediols and in situ cyclisation
Pridmore, Simon J.,Slatford, Paul A.,Taylor, James E.,Whittlesey, Michael K.,Williams, Jonathan M.J.
supporting information; experimental part, p. 8981 - 8986 (2009/12/27)
Alkyne-1,4-diols are readily available substrates which are isomerised to 1,4-diketones using Ru(PPh3)3(CO)H2/xantphos as a catalyst. In situ cyclisation into furans, pyrroles and pyridazines has been achieved under suitable conditions.
Scope of the suzuki-Miyaura cross-coupling reactions of potassium heteroaryltrifluoroborates
Molander, Gary A.,Canturk, Belgin,Kennedy, Lauren E.
supporting information; experimental part, p. 973 - 980 (2009/07/11)
A wide variety of bench-stable potassium heteroaryltrifluoroborates were prepared, and general reaction conditions were developed for their cross-coupling to aryl and heteroaryl halides. The cross-coupled products were obtained in good to excellent yields. This method represents an efficient and facile installation of heterocyclic building blocks onto preexisting organic substructures.
Ruthenium-catalysed conversion of 1,4-alkynediols into pyrroles
Pridmore, Simon J.,Slatford, Paul A.,Daniel, Aurélie,Whittlesey, Michael K.,Williams, Jonathan M.J.
, p. 5115 - 5120 (2008/02/09)
Various 1,2,5-substituted pyrroles have been synthesised from 1,4-alkynediols using a ruthenium catalysed isomerisation to give the corresponding 1,4-dicarbonyl compounds, which undergo in situ cyclisation to pyrroles in the presence of amine.
2,5-Disubstituted furans from 1,4-alkynediols
Pridmore, Simon J.,Slatford, Paul A.,Williams, Jonathan M.J.
, p. 5111 - 5114 (2008/02/09)
1,4-Alkynediols serve as readily available starting materials for isomerisation to 1,4-diketones, which can be converted in situ into the corresponding furans by acid-catalysed dehydration. A range of 2,5-disubstituted furans was prepared using the ruthenium-based catalyst Ru(PPh3)3(CO)H2 with Xantphos at 1 mol % loading.
