5216-04-6Relevant academic research and scientific papers
Ruthenium-Porphyrin-Catalyzed [4 + 2] Cycloaddition of α,β-Unsaturated Imines and Aldehydes
Maeda, Kazuki,Terada, Takuma,Iwamoto, Takahiro,Kurahashi, Takuya,Matsubara, Seijiro
, p. 5284 - 5287 (2015)
A new efficient synthetic route to unsymmetrically substituted dihydropyridine scaffolds via dehydrative [4 + 2] cycloaddition of N-tosylated α,β-unsaturated imines with aldehydes has been developed. This transformation is enabled by (i) the remarkable ca
N-Silylenamines as Reactive Intermediates: Hydroamination for the Modular Synthesis of Selectively Substituted Pyridines
Lui, Erica K. J.,Hergesell, Daniel,Schafer, Laurel L.
supporting information, p. 6663 - 6667 (2018/11/21)
A modular and selective synthesis of mono-, di-, tri-, tetra-, and pentasubstituted pyridines is reported. Hydroamination of alkynes with N-silylamine using a bis(amidate)bis(amido)titanium(IV) precatalyst furnishes the regioselective formation of N-silylenamines. Addition of α,β-unsaturated carbonyls to the crude mixtures followed by oxidation affords 47 examples of pyridines in yields of up to 96%. This synthetic route allows for the synthesis of diverse pyridines containing variable substitution patterns, including pharmaceutically relevant 2,4,5-trisubstituted pyridines, using this one-pot protocol.
Intramolecular carbolithiation of N-allyl-ynamides: An efficient entry to 1,4-dihydropyridines and pyridines - Application to a formal synthesis of sarizotan
Gati, Wafa,Rammah, Mohamed M.,Rammah, Mohamed B.,Evano, Gwilherm
, p. 2214 - 2222 (2013/02/23)
We have developed a general synthesis of polysubstituted 1,4-dihydropyridines and pyridines based on a highly regioselective lithiation/6-endo-dig intramolecular carbolithiation from readily available N-allyl-ynamides. This reaction, which has been successfully applied to the formal synthesis of the anti-dyskinesia agent sarizotan, further extends the use of ynamides in organic synthesis and further demonstrates the synthetic efficiency of carbometallation reactions.
De novo synthesis of 1,4-dihydropyridines and pyridines
Gati, Wafa,Rammah, Mohamed M.,Rammah, Mohamed B.,Couty, Francois,Evano, Gwilherm
supporting information; experimental part, p. 9078 - 9081 (2012/07/13)
An efficient and general method for the synthesis of 1,4-dihydropyridines and pyridines based on a lithiation/isomerization/intramolecular carbolithiation sequence is reported. This procedure provides an efficient, divergent, and straightforward entry to a wide range of polysubstituted dihydropyridines and pyridines starting from readily available N-allyl-ynamides.
Selenium dioxide-mediated methoxyhydroxylation of cyclic arylolefin
Chang, Meng-Yang,Lin, Chung-Han,Chen, Yeh-Long
scheme or table, p. 1430 - 1433 (2010/05/03)
Selenium dioxide-mediated methoxyhydroxylation of cyclic arylolefin with the modest yields is described. This facile strategy was also used to synthesize several 4-arylpyridines, 3-hydroxy-4-arylpyridines, and 3,4-diarylpyridines. Crown Copyright
A Pd(II)-catalyzed ring-expansion reaction of cyclic 2-azidoalcohol derivatives: Synthesis of azaheterocycles
Chiba, Shunsuke,Xu, Yan-Jun,Wang, Yi-Feng
supporting information; experimental part, p. 12886 - 12887 (2009/12/06)
(Chemical Equation Presented) A Pd(II)-catalyzed ring expansion-reaction of cyclic 2-azidoalcohol derivatives was found to proceed via an unprecedented C-C bond cleavage-C-N bond formation sequence, providing substituted azaheterocycles.
Synthesis of cis-3,4-diarylpiperidines and cis-3,4-diaryltetrahydropyrans
Chang, Meng-Yang,Lin, Chun-Yu,Hung, Ching-Yi
, p. 3312 - 3320 (2007/10/03)
Substituted cis-3,4-diarylpiperidines and cis-3,4-diaryltetrahydropyrans are synthesized in modest overall yields starting from 4-aryl-1,2,5,6-tetrahydropyridines and 4-aryl-1,2,5,6-tetrahydropyrans via the following sequence: (1) pinacol-type ring contraction having the?combination of m-chloroperoxybenzoic acid and boron trifluoride etherate, (2) Grignard addition with arylmagnesium bromide reagents and followed by boron trifluoride etherate-mediated intramolecular ring-expanded rearrangement, and (3) hydrogenation with hydrogen on 10% palladium-activated carbon. A facile synthesis of 3,4-diarylpyridines was also described by base-induced aromatization.
Ring Contraction Reactions of Dihydro- and Tetrahydrothiazepines to Isothiazolone Derivatives under Pummerer Conditions
Yamamoto, Kagetoshi,Yamazaki, Shoko,Murata, Ichiro,Fukazawa, Yoshimasa
, p. 5239 - 5243 (2007/10/02)
2,7-Diphenyl-5-oxo-2,3,4,5-tetrahydro-1,4-thiazepine (4) and 2,7-diphenyl-5-oxo-4,5,6,7-tetrahydro-1,4-thiazepine (5) were prepared from 2,3-dihydro-2,6-diphenyl-4H-thiopyran-4-one (1) through its O-tosyloxime (a mixture of syn and anti isomers ) followed
