Solid liquid phase transfer conditions

Far superior yields of l-(arylsulfonyl)-l//-azepines 16 are now available by a one-pot synthesis involving the action of sodium azide on an arylsulfonyl chloride under solid-liquid phase-transfer conditions which prevents the formation of acidic sulfonamides and, hence, the ring-contraction process.75 This procedure also has the advantage of avoiding the use of high pressures and the isolation and handling of the potentially explosive sulfonyl azides. 

Arylsulfonyl)-l//-azepines 16 Using Solid-Liquid Phase-Transfer Conditions General Procedure 75... 

The synthesis of quadrupolar chromophores has also been achieved from 2,6-DTT-dicarboxaldehyde 117. Push-push (i.e., bis-donor) compound 118 was prepared via a double Wittig reaction carried out under solid-liquid phase transfer conditions. Pull-pull (i.e., bis-acceptor) compounds 119 were obtained from a symmetrical bis-aldehydes via a double Horner-Emmons-Wittig condensation (Scheme 9) <2002SM17, 1999CC2055>. 

Herrmann WA, Brossmer C, Reisinger CP, Riermaier T, Ofele K, Beller M (1997) Coordination chemistry and mechanisms of metal-catalyzed C-C coupling reactions. Part 10. Palladacycles efficient new catalysts for the Heck vinylation of aryl halides. Chem Eur J 3 1357-1364 Iyer S, Jayanthi A (2001) Acetylferrocenyloxime palladacycle-catalyzed Heck reactions. Tetrahedron Lett 42 7877-7878 Iyer S, Ramesh C (2000) Aryl-Pd covalently bonded palladacycles, novel amino and oxime catalysts di- x-chlorobis(benzaldehydeoxime-6-C,AT)dipalla-dium(II), di- x-chlorobis(dimethylbenzylamine-6-C,A)dipalladium(II) for the Heck reaction. Tetrahedron Lett 41 8981-8984 Jeffery T (1984) Palladium-catalysed vinylation of organic halides under solid-liquid phase transfer conditions. J Chem Soc Chem Commun 1287-1289 (b) idem,... 

The nucleophilic attack on the bridging carbon results in two different reactivities. Usually ring opening occurs. Malononitrile under hydrolytic solid-liquid phase-transfer conditions attacks the methiodides 26 at the fusion carbon atom, thereby inducing ring opening and the formation of 4-(Ar-aryl-3 -methylisothioureido)-5-(dicyanomethylcnc)-l-... 

Times (h) needed to reach 50% conversion in the reaction of benzyl chloride with metal acetates in acetonitrile at ca. 25 °C under solid-liquid phase-transfer conditions ... 

Yamamura and Murahashi (1977) have studied the crown ether-catalysed cyanation of vinyl halides under solid—liquid phase-transfer conditions (20). The reaction of /rans-/ -bromostyrene [140] with sodium cyanide in benzene,... 

Jeffery, T. Palladium-Catalysed Vinylation of Organic Halides under Solid-Liquid Phase Transfer Conditions, J. Chem. Soc. Chem. Commun. 1984, 1287-1289. 

The group of Jew and Park successfully utilized dihydrocinchonidine-derived 6f as an efficient catalyst for the asymmetric alkylation of o-biphenyl-2-oxazoline- and o-biphenyl-2-thiazoline-4-carboxylic acid tert-butyl esters (16a and 16b) under mild solid-liquid phase-transfer conditions (Scheme 2.13) [32,33]. These reactions are... 

Whilst the use of Taddol as an asymmetric phase-transfer catalyst for asymmetric Michael reactions was only moderately successful, it was much more enantioselec-tive in catalyzing alkylation reactions. For this study, Belokon and Kagan employed alanine derivatives lib and 16a-c as substrates, and investigated their alkylation with benzyl bromide under solid-liquid phase-transfer conditions in the presence of 10 mol % of Taddol to form a-methyl phenylalanine, as shown in Scheme 8.8. The best results were obtained using the isopropyl ester of N-benzylidene alanine 16b as substrate and sodium hydroxide as the base. Under these conditions, (R)-a-methyl phenylalanine 17 could be obtained in 81% yield and with 82% ee [19]. Under the same reaction conditions, substrate 16b reacted with allyl bromide to give (R)-Dimethyl allylglycine in 89% yield and with 69% ee, and with (l-naphthyl)methyl chloride to give (R)-a-methyl (l-naphthyl)alanine in 86% yield and with 71% ee [20]. 

Under solid-liquid phase-transfer conditions, amino adds 17 and 25a,b were obtained from reactions using benzyl bromide, allyl bromide and 1-chloromethylnaphthalene, respectively, as the alkylating agents in the presence of 10 mol% of (S)-Nobin. Products 17 and 25a were obtained with >90% yield and 67-68% ee, whilst product 25b was obtained in only 60% yield and with only 18% ee, presumably due to the lower reactivity of the benzylic chloride-based alkylating agent. 

Vinylation of alkyl or aryl halides f The F J-catalyzed vinylation of organic halides can proceed at room temperature when conducted under solid-liquid phase-transfer conditions with BU4NCI as catalyst and NaHCO, a.s base. 

Pochini, A., Ihiglia, G., and Ungaro, R.,, Se-lective synthesis of phenolic Mannich bases under solid-liquid phases transfer conditions,... 

Halide and Azide Anions. These also open the epoxide re-gioselectively at the C-3 position. Addition of Li2CuBr4 results in bromide addition at the C-3 position of rac-(l), forming 3-bromo-1,2-propane 1-0-tosylate in 70-76% yield in THF or acetonitrile at It, or 1,3-dibromo-2-propanol in 82% yield in refluxing acetonitrile. Hydrofluorination takes place with KHF2 under solid-liquid phase transfer conditions, but the yield of fluorohydrin is very low (eq 3). Azidotrimethylsilane adds in the presence of a Lewis acid catalyst (eq 3). Addition of cyanide ion is achieved by using Diethylaluminum Cyanide in toluene. ... 

Alkylation of phthalimide anion can be carried out under solid-liquid phase-transfer conditions, using phosphonium salts or ammonium salts. In the reaction systems using hexadecyltributylphosphonium bromide, alkyl bromides and alkyl methanesulfonate are more reactive than alkyl chlorides. Octyl iodide is less reactive than the corresponding bromide and chloride. ( )-2-Octyl methanesulfonate was converted into (S)-2-octylamine with 92.5% inversion. Kinetic resolution of racemic ethyl 2-bromopro-pionate by the use of a chiral quaternary ammonium salt catalyst has been reported. Under liquid-liquid phase-transfer conditions, A -alkylation of phthalimide has been reported to give poor results. ... 

Activation with sulfonic acid chlorides is more general, rendering amides with the possible participation of symmetric anhydrides after disproportionation. This method has also found use in the synthesis of modem 3-lactam antibiotics. However, in peptide chemistry this activation method leads to unwanted side reactions, like formation of nitriles in the cases of glutamine and asparagine, and racemization. In a convenient one-pot procedure, the carboxylic acids are activated by sulfonyl chlorides under solid-liquid phase transfer conditions using solid potassium carbonate as base and a lipophilic ammonium salt as catalyst. ... 

Heck-type vinylations of alkynic halides proceed only under solid-liquid phase-transfer conditions. These mild conditions allow the reaction to be performed with thermily unstable substrates. Thus, methyl ( )-enynoates can be obtained from the reaction of 1-iodoalkynes with methyl 2-propenoate in DMF at room temperature in the presence of potassium carbonate, tetrabutylammonium chloride and a catalytic amount of palladium acetate (Scheme 36)." ... 

Compound 27b was subjected to the same reaction conditions as those for the cyclization of 27a to afford 28b in a better yield (60%, Table 5, Entry 4). The reaction under solid-liquid phase transfer conditions at 100°C using a catalytic amount of tetra- -butylammonium chloride (/7-BU4NCI) in N, A -dimethylformamide (DMF) [83] was found to be extremely effective to afford 28b in a much improved yield (Table 5, Entry 6, 77%). 

Unsymmetrical bis(pyrazolyl)methanes can be obtained according to a general procedure published by Elguero in 1986.222 The pyrazole was transformed into its 1-hydroxymethyl derivative by the action of formaldehyde. The 1-hydroxymethyl derivative then reacted with thionyl chloride to produce the 1-chloromethyl derivative which was isolated as its hygroscopic hydrochloride salt. Then under solid liquid phase transfer conditions the 1-chloromethylpyrazole reacts with one equivalent of 3,4,5-trimethylpyrazole to selectively produce the unsymmetrical bis(pyrazolyl)-methane. 

Sinisterra, J.V., Mouloungui, Z., Delmas, M., and Gaset, A., Barium hydroxide as catalyst in organic reactions. Part 5. Application in the Homer reaction under solid-liquid phase-transfer conditions. Synthesis, 1097, 1985. 

Grouiller, A., H. Essadiq, B. Najib, and P. Moliere, Regioselective o-p-Toluenesulfonylation of Nucleosides under Solid/Liquid Phase-Transfer Conditions, Synthesis, 7/2/(1987). 

Catalytic benzylation of 10 was performed under solid-liquid phase-transfer conditions to yield benzylidenemalononitrile Alkylidenemalononitriles can undergo reduction to yield the corresponding saturated malononitriles ". Aryl malononitriles 125 have been obtained from 10 and halobenzenes " or from aroyl chlorides in three steps. Surprisingly, the aliphatic malononitrile derivative 126 has been obtained when 2-indolone was reacted with 43. The same reaction was also observed for two other cyclic carbonyl compounds... 

Under solid-liquid phase transfer conditions both primary and secondary alcohols react with 2,4,6-trichloro-l, 2,5-triazine to give the corresponding mono or dialkoxy derivatives depending on the reagent molar ratios [94SC21S3]. 

Autoxidation of weak carbon acids under solid-liquid phase transfer conditions... 

---