15150-84-2Relevant articles and documents
Synthesis of functionalized 3-arylpyridazines via Pd-catalyzed decarboxylative cross-coupling of pyridazine-3-carboxylic acids
Wang, Shengqiang,Lu, Hongtao,Li, Jingya,Zou, Dapeng,Wu, Yusheng,Wu, Yangjie
, p. 1107 - 1111 (2017)
An efficient and general protocol for the decarboxylative cross-coupling of pyridazine-3-carboxylic acids with aryl-bromides has been described. This method provides a new avenue for the synthesis of 3-arylpyridazines via decarboxylative cross-coupling strategy by employing the dual-catalyst system of Pd(PPh3)4/Cu2O in the presence of Li2CO3at 160?°C in DMA.
Copper-catalyzed aerobic 6-endo-trig cyclization of β,γ-Unsaturated Hydrazones for the Divergent Synthesis of Dihydropyridazines and Pyridazines
Fan, Zhenwei,Pan, Zhangjin,Huang, Liangsen,Cheng, Jiajia
, p. 4236 - 4245 (2019/04/30)
A divergent synthetic strategy to 1,6-dihydropyridazines and pyridazines through Cu(II)-catalyzed controllable aerobic 6-endo-trig cyclization was developed. The selectivity can be rationally tuned via the judicious choice of reaction solvent. It was found that the 1,6-dihydropyridazines were obtained in moderate to high yields with CH3CN as the reaction solvent, whereas employment of AcOH directly afforded pyridazines in up to 92% yields, probably arising from the oxidation of the in situ generated 1,6-dihydropyridazines.
Lewis Acid Directed Regioselective Metalations of Pyridazine
Balkenhohl, Moritz,Jangra, Harish,Lenz, Tobias,Ebeling, Marian,Zipse, Hendrik,Karaghiosoff, Konstantin,Knochel, Paul
supporting information, p. 9244 - 9247 (2019/06/04)
Mono- or bidentate boron Lewis acids trigger a regioselective magnesiation or zincation of pyridazine in position C3 (ortho product) or C4 (meta product). The regioselectivity of the metalation was rationalized with the help of calculated pKa values of both pyridazine and pyridazine/Lewis acid complexes.
Copper-Promoted 6- endo-trig Cyclization of β,γ-Unsaturated Hydrazones for the Synthesis of 1,6-Dihydropyridazines
Guo, Yong-Qiang,Zhao, Mi-Na,Ren, Zhi-Hui,Guan, Zheng-Hui
, p. 3337 - 3340 (2018/06/11)
A novel and efficient strategy for the synthesis of 1,6-dihydropyridazines via copper-promoted 6-endo-trig cyclization of readily available β,γ-unsaturated hydrazones have been developed. A series of 1,6-dihydropyridazines have been synthesized by this method with good yields, high functional group tolerance, and remarkable regioselectivity under mild conditions. Importantly, the 1,6-dihydropyridazines can be efficiently converted to biologically important pyridazines in the presence of NaOH.
Selective aryl radical transfers into N-heteroaromatics from diaryliodonoium salts with trimethoxybenzene auxiliary
Dohi, Toshifumi,Ueda, Shohei,Hirai, Akiko,Kojima, Yusuke,Morimoto, Koji,Kita, Yasuyuki
, p. 1272 - 1284 (2019/11/14)
We have found that a series of trimethoxybenzene-based diaryliodonium(III) salts I (ArI+Ar’X-, where Ar = various aryl groups, Ar’ = 2,4,6-trimethoxyphenyl, X- = counterion) can exclusively cause Ar-transfers during the base-induced radical couplings with N-heteroaromatic compounds 1 by working the trimethoxybenzene ring (Ar’) as an inert coupling auxiliary. By the treatment with N-heteroaromatics 1 as the solvent, the metal-free arylations utilizing the specific salts I initiated by solid NaOH upon heating selectively produced the corresponding biaryls 2 in good yields without the formation of the trimethoxybenzene (Ar’) coupling product.
Synthesis of Functionalized β-Keto Arylthioethers by the Aryne Induced [2,3] Stevens Rearrangement of Allylthioethers
Thangaraj, Manikandan,Gaykar, Rahul N.,Roy, Tony,Biju, Akkattu T.
, p. 4470 - 4476 (2017/04/28)
A mild and transition-metal-free synthesis of β-keto arylthioethers has been developed by the aryne triggered [2,3] Stevens rearrangement of allylthioethers. The key sulfur ylide intermediate for the rearrangement was formed by the S-arylation of allylthi
Pyridazine N-Oxides as Precursors of Metallocarbenes: Rhodium-Catalyzed Transannulation with Pyrroles
Kanchupalli, Vinaykumar,Joseph, Desna,Katukojvala, Sreenivas
supporting information, p. 5878 - 5881 (2015/12/11)
Pyridazine N-oxides are used for the first time as precursors of metallocarbenes. These nitrogen-rich heterocycles led to the discovery of a novel acceptor and donor-acceptor enalcarbenoids. The synthetic utility of these metallocarbenes was demonstrated in the rhodium-catalyzed denitrogenative transannulation of pyridazine N-oxides with pyrroles to the valuable alkyl, 7-aryl, and 7-styryl indoles. The transannulation strategy was applied to the synthesis of a potent anticancer agent.
Potassium t-butoxide alone can promote the biaryl coupling of electron-deficient nitrogen heterocycles and haloarenes
Yanagisawa, Shuichi,Ueda, Kirika,Taniguchi, Tadashi,Itami, Kenichiro
supporting information; scheme or table, p. 4673 - 4676 (2009/05/13)
(Chemical Equation Presented) The biaryl coupling of electron-deficient nitrogen heterocycles and haloarenes can be promoted by potassium t-butoxide alone, without the addition of any exogenous transition metal species. Electron-deficient nitrogen heterocycles such as pyridine, pyridazine, pyrimidine, pyrazine, and quinoxaline are arylated with haloarenes. Control experiments support a radical-based mechanism. Taking these findings into account, radical processes may be partially involved in the reported transition-metal-catalyzed arylation reactions employing t-butoxide bases and haloarenes under elevated temperatures or under microwave irradiation.
Use of N-oxide compounds in coupling reactions
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Page/Page column 16; 17; 26-27, (2008/12/05)
Metal-catalyzed coupling process comprising reacting a compound of general formula 1 with a compound A-X, to obtain a compound of general formula 2, which may further be converted to a compound of general formula 3
Palladium-catalyzed cross-coupling reactions of diazine N-oxides with aryl chlorides, bromides, and iodides
Leclerc, Jean-Philippe,Fagnou, Keith
, p. 7781 - 7786 (2007/10/03)
New aspects of N-oxides: Pyrazine, pyridazine, and pyrimidine N-oxides are regioselectively arylated with aryl iodides, bromides, and chlorides in the presence of a palladium catalyst (see scheme). The resulting products can be deoxygenated in high yield
