Benzoyl acetylen

Triazole Derivatives. Triazole derivatives are known to possess tumor necrosis factor-a (TNF-a) production inhibitor activity. The synthesis of triazole derivatives can be achieved from alkynes or diynes by a tandem cascade reaction involving 1,3-dipolar cycloaddition, anionic cyclization and sigmatropic rearrangement on reaction with sodium azide. Some of the benzoyl triazole derivatives were considered to be potent local anaesthetics and are comparable with Lidocaine. The triazoles can also be prepared from benzoyl acetylenes,triazoloquina-zoline derivatives, 2-trifluoromethyl chromones, aliphatic alkynes, 2-nitroazobenzenes, ring opening of [ 1,2,4]triazolo [5,1-c] [2,4]benzothiazepin-10 (5//)-one, alkenyl esters and dendrimers. A number of these reactions are outlined in eqs 44 8. 

The polymers were first described by Newkirk. Polymerisation may be brought about by subjecting acetylene-free vinyl fluoride to pressures to up to 1000 atm at 80°C in the presence of water and a trace of benzoyl peroxide. 

Free-radical additions of trichlorosilane to acetylenes initiated by benzoyl peroxide were stereospecific trans additions, giving only cis adducts. The same workers observed that tri-n -butyl amine also catalyzed addition of trichlorosilane to phenylacetylene but gave a mixture of cis- and trans -l-phenyl-2-trichlorosilylethene, 1,1-phenyltrichlorosilylethene, and 1-phenyl-l,2-bistrichlorosilylethane (54). No stereospecificity was observable with the amine as catalyst. 

Anhydro-D-mannitol is also obtained by a novel route from 1,6-dibenzoyl-D-mannitol. When this compound is heated with p-tolu-enesulfonic acid in acetylene tetrachloride, it suffers partial dehydration and one of the products is a dibenzoyl derivative of mannitan. On debenzoylation of this substance it yields crystalline 1,4-anhydro-D-mannitol.67 The formation of dibenzoyl-1,4-anhydro-D-mannitol has involved the migration of at least one benzoyl group and Hockett and coworkers6 believe that the initial product is either 2,6- or 3,6-dibenzoyl-1,4-anhydro-D-mannitol. 

The oxygen transfer to the -acetylenic carbon results in the very intense benzoyl cation, whereas the transfer to the a-carbon, via a series of fragments corresponding to the loss of OH , CO and CO2, respectively, leads to annelated heterocycles such as the radical cation of carbazole, as a result of elimination of CO81. The generation of the benzoyl cation was rationalized as shown in Scheme 1281. 

Domino-Heck Reactions-General Procedure 5.6 mg (25 pmol) of palladium(II) acetate and 55 pmol of the arsine ligand were dissolved in 3 ml of dry dimethyl formamide and the solution was stirred at 65°C (40°C for trimethylsilylacetylene) for 15 mitt Then, 127 mg (1.35 mmol) N-Benzoyl-2-azabicyclo[2.2.1]hept-5-en-3-one, 1 mmol of the aryl compound. Four hundred and eighty-eight microliters (3.50 mmol) of triethylamine, and 3.00 mmol of the phenylacetylene (or silylmethyl-acetylene) were added rapidly in one portion. The mixture was heated at the same temperature for 24 h. After cooling down to room temperature 50 ml of brine were added, the reaction mixture was extracted with ethyl acetate and dried over MgSO. The solvent was evaporated, the residue purified by column chromatography (n-Hexan-Ethyl acetate 4 1). 

In addition to studying the behavior of benzoyl chloride. Cheek and Horine [72] have examined the reduction of benzoyl fluoride electrolysis of the latter compound affords benzyl benzoate, diphenyl-acetylene, stilbenol benzoate, and some polymers. Another feature of the reduction of benzoyl chloride is the possibility that both acyl radicals and acyl anions are involved as intermediates [71]. 

In general, acyl azides are too unstable to survive at the temperatures required for addition to acetylenes, although benzoyl azide adds readily to ynamines in toluene. Ethoxycarbonyl azide also gives triazoles in good yield with ynamines. The azide adds to propargylic alcohols in boiling ethanol, and to acetylene at 100° under pressure. Addition to phenylacetylene and to electron-deficient acetylenes has been carried out at 130°. Oxazoles are also formed at this temperature by competing thermal decomposition of the azide, and addition of ethoxycarbonylnitrene to the acetylenes. The triazole obtained from phenylacetylene is 2-ethoxycarbonyl-4-phenyltriazole the two 1-ethoxycarbonyltriazoles can be isolated if the addition is carried out at 50° over several weeks. Since the IH- to -triazole isomerization takes place readily in these systems, a IH-structure cannot be assumed for a triazole formed by addition of these azides. 

Other li acetylides Li-C=C-R with R = hexyl [21] or benzylether dendrons [22, 23] (up to the fourth generation) have also been attached to (Figure 3.3), and various different electrophiles have been used to complete the reaction with the intermediate li-fuUeride (Scheme 3.2 and Figure 3.3). Besides the protonation, alkyl-, benzyl-, cycloheptatrienyl-, benzoyl- or vinylether-derivatives or formaldehyde and dichloro-acetylene were used as electrophiles [12,20]. Most of these electrophiles are attached to the anion in the expected C-2 position. The 1,4-adducts are available by quenching the anion with the tropylium cation or benzoyl chloride [12]. The fuUerene anion can be stabilized by introduction of benzylether dendrons. The lifetimes of the anions change with the size of the dendrons [22]. 

H. R = COPh) has been prepared from the nitrile (99, R = Me) and benzoyl chloride followed by treatment with sodium hydrogen carbonate. This compound (98, R = R = Ph, R - Me, R = H, R = COPh) undergoes a 1,3- polar cycloaddition with dimethyl acetylene-dicarboxylate in boiling benzene during 10 minutes, yielding the pyrrole... 

Perfluoroalkynylzinc reagents do not generally undergo direct acylation or allylation. One exception, however, is reaction of bis(trifluoropropynyl)zinc with benzoyl chloride, without catalyst, to give the aroyltrifluoromethyl acetylene (equation 97)98. 

An example of 2,4,6-triphenylpyrylium-3-olate (65 R = R = R = Ph, R = H) reacting as a 1,3-dipole was first provided by Suld and Price who obtained a maleic anhydride adduct (C25HigO5). Subsequently, an extensive study of the cycloadditions of this species has been published by Potts, Elliott, and Sorm. With acetylenic dipolarophiles, compound 65 (R = R = R = Ph, R = H) gives 1 1 adducts that have the general structure 74 and that isomerize to 6-benzoyl-2,4-cyclohexadienones (76) upon thermolysis. This thermal rearrangement (74 -> 76) has been interpreted in terms of an intermediate ketene 75. The 2,3-double bond of adduct 74 (R = Ph) is reduced by catalytic hydrogenation. Potential synthetic value of these cycloadducts (74) is demonstrated by the conversion of compound 74 (R = Ph) to l,2,3,4,6-pentaphenylcyclohepta-I,3,5-triene (79 R= Ph) via the alcohol 78 (Scheme 1). ... 

Finally, a recent paper reports that under kinetic conditions (25 °C/6 h) phenoxide and thiophenoxide add to benzoyl(trifluoromethyl)acetylene (580 equation 133), 1,4 to the trifluoromethyl group rather... 

Benzyl halides have been reported to react with nickel carbonyl to give both coupling and carbonylation (59). Carbonylation is the principal reaction in polar nonaromatic solvents, giving ethyl phenylacetate in ethanol, and bibenzyl ketone in DMF. The reaction course is probably similar to that of allylic halides. Pentafluorophenyl iodide gives a mixture of coupled product and decafluorobenzophenone. A radical mechanism has been proposed (60). Aromatic iodides are readily carbonylated by nickel carbonyl to give esters in alcoholic solvents or diketones in ethereal solvent (57). Mixtures of carbon monoxide and acetylene react less readily with iodobenzene, and it is only at 320° C and 30 atm pressure that a high yield of benzoyl propionate can be obtained (61). Under the reaction conditions used, the... 

AIBN = 2,2 -azobisisobutyronitrile 9-BBN = 9-borabicyclo [3.3.1]nonane Bn = benzyl BOC = f-butoxycarbonyl Bz = benzoyl CAN = ceric anunoninm nitrate Cp = cyclopenta-dienyl Cy = cyclohexyl DAST = diethylaminosnllur trifln-oride DBA = l,3-dibromo-5,5-dttnethylhydantoin DDQ = 2,3-dichloro-5,6-dicyano-l,4-benzoquinone DET = diethyl tartrate DIAD = diisopropyl acetylene dicarboxylate DIBAL-H = diisobutylalummum hydride DIPEA = diisopropyl ethyl amine DMDO = dimethyldioxirane HMPA = hexamethylphosphortriamide EDA = lithium diisopropy-lamide Ms = methylsulfonyl MOM = methoxymethyl NBS = iV-bromosuccmimide NMO = A-methylmorpholine iV-oxide PDC = pyridinium dichromate PMP = p-methoxyphenyl THP = tetrahydropyranyl TIPS = trisiso-propylsilyl TMANO = trimethylamine A-oxide TBDMS = t-butyldimethylsilyl Tf = trifluoromethanesulfonyl TMP = 2,2,6,6-tetramethylpiperidyl TMS = trimethylsilyl Ts = p-toluenesulfonyl. 

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