Reactions of alcohols with α-alkoxyacroleins at room temperature

The first stage of the reactions of alcohols with α-alkoxyacroleins in an acidic medium at 20°C under kinetically controlled conditions is the Markovnikoff addition at the C=C bond to form 2,2-dialkoxypropanals (methylglyoxal ketals). Under conditions of thermodynamic control, subsequent acetalization of the aldehyde group occurs to form 1,1,2,2-tetraalkoxypropanes. When the duration of the reaction is further increased in the absence of a water acceptor, the ketal group undegroes hydrolysis and methylglyoxal acetals are formed. A method was developed for the preparation of methylglyoxal ketals. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2504–2507, December, 1998.     

Reaction of α-alkoxyacroleins with thiols

Conclusions The nucleophilic or radical addition of thiols to -alkoxyacroleins leads to 2-alkoxy-3-organylthiopropanals. Depending on the reaction conditions, the product of the electrophilic reaction of the same reagents is a 2-alkoxy-2-organylthiopropanal or 1-alkoxy-1-organylthiopropanone.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 722–724, March, 1986.     

Reaction of α-alkoxyacroleins with acetone cyanohydrin

Conclusions -Alkoxyacroleins add acetone cyanohydrin in the presence of piperidine to give 1-N-piperidino-1-cyano-2-alkoxy-2-propenes, which in the presence of piperidine or on long storage are isomerized to 1-N-piperidino-1-cyano-2-alkoxy-1-propenes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2122–2124, September, 1973.     

Reactions of 2H-tellurochromene

2-H-Tellurochromene is characterized by reactions (halogenation, alkylation, and complex-formation) which result in an increase in the coordination number of the tellurium atom to 4 or 3, to give -telluranes, telluronium salts, and complexes with metal salts. Oxidation of 2-H-tellurochromene with trityl perchlorate affords tellurochromyllium perchlorate, and with dichromate 2-formylbenzo [b] tellurophene.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1050–1054, August, 1988.     

Reactions of 2-hydroxybenzonitrile with isocyanates

Triethylamine catalyzes the reaction of 2-hydroxybenzonitrile ( 1 ) with aryl isocyanates to form the corresponding carbamates 2a-c , as well as the cyclization of the latter compounds to either 4[N-(N-arylcarbamoyl)-imino]-3-aryl-2H-1,3-benzoxazin-2-ones 4a-c , or 4-arylamino-2H-1,3-benzoxazin-2-ones 7a-c , depending on the reaction temperature. Under analogous conditions, the carbamates obtained from 1 and 2-chloroethyl isocyanate, 3-chloropropyl isocyanate and ethyl isocyanatoacetate undergo a double cyclization yielding imidazo- and pyrimido[1,2-c|1,3]benzoxazinones 13a,b,17 . Upon heating in phenyl ether, compounds 7a-c , rearrange to 2-(2-hydroxyphenyl)-4(3H)-quinazolinones 10a-c .     

氯化钯催化的交叉偶联反应

钯催化的交叉偶联反应已经成为有机合成化学中构建C-C键最重要的方法之一.其中,氯化钯及其配合物所组成的催化体系具有高效、高选择性、稳定以及价廉等优点,因而在交叉偶联反应中得到较为广泛的应用.综述了氯化钯及其配合物催化的交叉偶联反应,其中包括Suzuki反应、Stille反应、Hiyama反应和Kumada反应等.     

Reactions of 2-arylhydrazonoacetamidoximes with orthoesters

The reactions of 2-arylhydrazono-2-carbamoylacetamidoximes with orthoesters afford either 3-arylhydrazono-1,2,4-oxadiazoles or 1,2,3-triazoles, depending on the reactant structure.     

Reactions of 2-acyl-1,3-indandiones

2-Pivaloyl-1,3-indandione reacts with thiosemicarbazide in aqueous base, through two successive retro-Claisen reactions, to yield 1-hydroxy-4-methylphthalazine. The mechanism of this reaction is described. Under similar conditions, 2-benzoyl and 2-acetyl-1,3-indandione, did not undergo the same reaction, a steric factor is considered.     

2-Aminoethanols in Transacetalization Reactions

Symmetric and mixed nitrogen-containing acetals and enol ethers were synthesized in an overall yield of 46-63% by reactions of N,N-dialkylaminoethanols with diethyl acetals derived from cyclohexanone, cyclopentanone, and acetophenone.     

Reactions of 2-amino- and 2-hydrazinobenzimidazoles with 2-acyldimedones

The reaction of 2 formyldimedone with 2-amino- and 2-hydrazinobenzimidazoles at 20°C in ethanol gave 2-(2-benzimidazolyl)aminomethylene- and 2-[2-(2-benzimidazolyl)hydrazinomethylene]-5,5-dimethylcylohex-anediones, while this reaction carried out in ethanol at reflux in the presence of acid gave 2,2-dimethyl-4-oxo 1, 2, 3, 4-tetrahydroquinazolino(1, 2-a]benzimidazole and 1-(2-benzimidazolyl)-6, 6-dimethyl-4-oxo-4, S, 6, 7-tetrahydroindazole, respectively.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 247–252, February, 1996.