Pyridines, substituted synthesis

Imidazo[l,2-n]pyridine, 5-methyl-2-methylthio-3-substituted synthesis, 5, 632... 

Palladium, (diammine)bis(thiocyanato)-isomerism, 1, 185 Palladium, dichlorobis(amine)-substitution reactions stereochemistry, 1, 318 Palladium, dichlorobis(pyridine)-substitution reactions, 1, 314 Palladium, dinitritobis(triisopropylphosphine)-substitution reactions, I, 314 Palladium, ethylene-synthesis... 

Rayama, A., Rinoshita-Nagaoka, J., Rawano, H., Rameda, S. and Mukuriya, M. (1998) Cycloauration of 2-substituted pyridine derivatives. Synthesis, structure and reactivity of srx-membered cycloaurated complexes of 2-anilino-, 2-phenoxy- and 2-(phenylsulfanyl)-pyridine. Journal of the Chemical Society Dalton Transactions, (24), 4095. 

Akiba, K.-y., Matsuoka, H., and Wada, M., Regiospecific introduction of alkyl groups into 4-position of pyridine — novel synthesis of 4-substituted py-... 

Benzofurans. 2-Substituted benzofurans can be obtained in 65-83% yield by reaction of o-iodophenols and 1-alkynes in the presence of Cu20 suspended in pyridine. This synthesis has been conducted in the past by reaction of copper(I) acety-lides with o-halophenols, but yields are somewhat lower. In addition, copper(I) acetylides can be explosive. 

This method has found particular use in the preparation of pyridine-substituted dithiolene complexes, which exhibit pH sensitive luminescence properties (263). The a-halocarbonyl starting materials could include related precursors used in the synthesis of unsaturated dithiocarbonates described in Section II.C. 

Most recently, the methods of template-directed solid-state synthesis were employed to constmct the [3]- and the [5]-ladderane. The construction involved a resorcinol derivative (5-methoxyresorcinol) as a linear template to organize pyridine-substituted polyenes for the reaction within discrete molecular assemblies in solids. The assemblies are... 

Also included in this section are procedures for the synthesis of the chromium analog and a pyridine substituted vanadium(II) saccharinate. All of these compounds are potentially useful in the synthesis of other metal(II) compounds. They are prepared in good yields and with high purity. 

Extension by Vicarious Nucleophilic Aromatic Substitution Synthesis of Imidazo[4,5-c]pyridines... 

Irradiation of chlorobenzene solutions of [Pd(PPh3)4] produces trans-[PdCl2(PPh3)2] and a mixture of chlorobiphenyls, and irradiation of 2-amino-5-iodo-3-(N-methyl-N-tosylamino)pyridine in benzene solution gives 2-amino-3-methylamino-5-phenylpyridine by simultaneous phenylation and tosyl removal. This reaction is a key step in the synthesis of the food-borne carcinogen 2-amino-l-methyl-6-phenylimidazo[4,5-b]pyridine. Substituted 1,2 -biazulenes have been prepared by photolysis of 2-diazo-l,3-dicyanoazulen-6(2H)-one in the presence of azulene derivatives. ... 

HC(44/3)l>. The two most important methods are (i) conversion of thienyllithium to a thienyl-boronic acid by reaction with alkyl borate, followed by oxidation with H2O2, and (ii) reaction of thienylmagnesium derivatives with t-butylperbenzoate, followed by dealkylation of the /-butyl ethers with acid. The boronic acid method has been used for the synthesis of several pyridine-substituted hydroxy thiophenes <92ACS654>. 

Pyridine-substituted nicotines, nornicotines, and anabasines are available from a-cyano-amines by a new synthesis. The syntheses of ( )-[l - N]nornicotine and ( )-[l - N]nicotine have been described, from cyclopropyl 3-pyridyl ketone and [ N]formamide. 4-Methylnicotine has been prepared it shows no nicotine-like pharmacological activity. " An investigation into the stereochemical factors involved in the behaviour of nicotine and related compounds in the Menschutkin reaction has been conducted.A bridged nicotine , 1,2,3,5,6,10b-hexahydropyrido[2,3-g]indolizine (44), has been synthesized by carboxylation of the dilithium derivative of 2-methylnornicotine followed by cyclisation and reduction with borane in tetrahydrofuran. Several 5-halogeno-nicotines have been prepared and their pK values and biological activities measured. ... 

The Bohlmann-Rahtz synthesis is viable for the construction of di- or tri-substituted pyridines and has been applied in the synthesis of complex target molecules. The Baldwin group was one of the first to employ this method for the construction of pyridine substituted a-amino acids. Exposure of alkynyl ketone 182 to 3-aminocrotoyl ester 183 or ketone 184 in ethanol at reflux gave rise to the desired pyridyl-P-alanines 185 and 186, respectively, which were subsequently deprotected to afford the a-amino acid L-azatyrosine analogues 187 and 188, respectively. 

---