Appel conditions

Bergin E, O Connor CT, Robinson SB, McGarrigle EM, O Mahony CP, Gilheany DG (2007) Synthesis of F-stereogenic phosphorus compounds. Asymmetric oxidation of phosphines under Appel conditions. J Am Chem S[Pg.228]

Rajendran KV, Kennedy L, Gilheany DG (2010) P-Stereogenic phosphoms compounds effect of aryl substituents rai the oxidation of aTylmethylphcmylphosphanes under asymmetric Appel conditions. Eur J Org Chtan 5642-5649... 

Syntheses of Dexelvucitabine (127) [150] and later - Elvucitabine (126) [151] were described, starting from D- and L-xylose, respectively, both using almost the same methodology. In particular, D-xylose was transformed into the dibenzoyl derivative 181 using standard manipulations (Scheme 41). Under modified Appel conditions (U/PPhj/imidazole), 181 gave unstable glycal 182, which reacted with fluorocytosine derivative 158 and iV-iodosuccinimide to yield 183. Compound 183 was subjected to reductive elimination and deprotection to give 127. 

Denton RM, Tang X, Przeslak A. Catalysis of phosphoms (V)-mediated transformations dichlorination reactions of epoxides under appel conditions. Org. Lett. 2010 12(20) 4678 681. 

Scheme 1.59 Gilheaney s stoichiometric asymmetric oxidation approach towards phosphines under Appel conditions...

Behavioral Pharmacology of Hallucinogens in Animals Conditioning Studies James B. Appel and John A. Rosecrans... 

Ketenimines (144), generated from a-substituted benzophenone 1-acetamidoethyl-idenehydrazones with a mixture of triphenylphosphine, carbon tetrachloride and triethylamine in dichloromethane (Appel s conditions), have been used to synthesize a variety of 1,2,4-triazole-fiised heterocycles (see Scheme 56). Mechanistically, the... 

Federal and state lawmakers should enact laws providing that in the absence of extraordinary circumstances clearly stated on the record and subject to appellate review, the use of pharmacotherapy may not be imposed as a term of a criminal sentence, or as a condition for parole or probation. 

An extensively studied and highly important 1,2,3-dithiazole - 4,5-dichloro-l,2, 3-dithiazol-l-ium chloride (Appel salt) 145 (R = Cl) - was first prepared by Appel and coworkers in 1985 by chlorination of chloroacetonitiile by sulfur monochloride in dichloromethane (1985CB1632) and it has been the most convenient procedure to date. Appel salt can be obtained also by prolonged chlorination of acetonitrile itself, or by the sulfur monochloride reaction with ethylamine the yields and experimental conditions were not disclosed (1985PS277). Recently, a series of mono-substituted acetonitriles were converted to 5-substituted-4-chloro-l,2,3-dithiazolium chlorides 145 (1999CC531,... 

The extensively studied Appel s salt can be produced by prolonged chlorination of acetonitrile with S2CI2 (Scheme 24) <85CB1632>. For preparative purposes chloroacetonitrile gives the best yield (85%). Another simple method for synthesis of Appel s salt may be provided by reaction of S2CI2 with ethylamine (yield and conditions of the process not disclosed) <85PS(23)277>. 

Oxybutynin and tolterodine (Wein et ah, 1991 Appel et ah, 2000), can be more effective than other agents in these conditions, probably because of the high prevalence of detrusor instability (Koff, 1988 Wein et ah, 1991 Sullivan and Abrams, 1999 Appel et ah, 2000 Curran et ah, 2000). Diurnal enuresis and dysfunctional voiding in particular, but even urinary frequency and dysuria, can be very distressing to children and are often publicly obvious. Distress may lead... 

While studying the chemistry of 4,5-dichloro-l,2,3-dithiazolium chloride (Appel s salt) and its derivatives, Besson reported the synthesis of various benzothiazoles from N-arylimino-l,2,3-dithiazoles, which could be synthesised from commercially available aromatic amines28. In this work, the authors explored a variety of strategies to construct the benzothiazole ring and demonstrated that in all cases the focused microwave methodologies were more productive and under well-defined conditions provided convenient methods for scale-up (Scheme 3.17)28. Comparisons were also made between reactions performed under solvent-free conditions and in the presence of solvent29. It is noteworthy that there is no general rule and some reactions performed in the presence of solvent may sometimes be more convenient than the same dry media reaction. 

The reaction of the secondary alcohol with trioctylphosphine and carbon tetrabromide results in the formation of the 13. The conditions are similar to those established by Appel et al. for the conversion of alcohols to chlorides. The transformation proceeds through an Sn2 mechanism resulting in inversion of the configuration.18... 

The resulting propargylic alcohol is protected as TIPS ether by a standard procedure using the corresponding silyl chloride and imidazole in DMF. Optionally the more reactive silyl triflate and 2,6-lutidine may be employed in order to shorten the reaction time. Under acidic conditions TIPS and TPS are nearly stable protecting groups. Therefore the TBS ether is selectively cleaved with acetic acid even in presence of the acetal moiety.13 Subsequent reaction with iodine and triphenylphosphine, known as the Appel reaction14, provides the desired iodide 4. 

In a similar transformation of ylidene 104, obtained from Appel salt 20 and Meldrum s acid, with primary aliphatic amines, the reaction has been stopped at the stage of (alkylamino)cyanomethylidene 105 <2000J(P1)3107>. Ethylene diamine and other diamines gave under the same conditions imidazolidin-2-ylidenes... 

In the late 1950s several perfumers and perfume chemists proposed that fragrance performance, in all media and applications, is largely dependent upon the rates of evaporation of the individual perfume materials under the specific conditions in which the fragrance is evaluated (Pickthall 1956 Sfiras and Demeilliers 1956 Jellinek 1959). They stressed the importance of knowing the vapor pressures of perfume materials (Appell 1964). They suggested that differences in the performance of a given odorant in different media are caused by the attraction forces between odorant and product base, and that these forces could be understood and predicted from the chemical structures of the materials involved (Jellinek 1961 Dervichian 1961). 

The synthesis of novel 2-cyanothiazolecarbazole analogues of ellipticine has been reported. The 3-aminocarbazole 36 was treated with 4,5-dichloro-l,2,3-dithiazolium chloride (Appel s salt 37) to give the imino-l,2,3-dithiazole 38. Rearrangement of 38 under thermal conditions gave 39 in moderate yield <02TL2482>. 

Semarquons que ces derniers morphismes sont fonctoriels en F, et par construction respectent les structures de modules dkduites de celle de F (ce que nous avons appel Lie (F/S,M) au second membre). Si F/S verifie (E), comme ces morphismes sont galement fonctoriels en M, ils respectent galement les structures de modules dkduites de celle de M k l aide de la condition (e), e est-k-dire celles not es Lie. ... 

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