Alkylation chemistry

Oshima and coworkers have reported that treatment of tertiary alkyl fluorides with diphenylphosphine in the presence of a stoichiometric amount of BF3 OEt2 gives rise to the corresponding tert-alkyldiphenylphosphine tetrafluoroborate salts, which can be trapped by elemental sulfur to give the phosphine sulfides (144) (Equation 86) [88]. Remarkably, this reaction works despite the presence of the highly coordinating Lewis basic phosphine. 

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This article covers important industrial technologies and the direction of future technological development. The description of alkylation chemistry and conventional alkylation technologies covered in the eadier editions of this Eniyclopedia and other references is minimized (1,2) (see also Eriedel-Crafts reactions). 

Although the Ziegler reaction provides a more direct method for produciag primary alcohols, aluminum alkyl chemistry requires special handling and is fairly cosdy. The by-product aluminum salts usuaUy require some treatment for disposal (115). 

R. M. Roberts and A. A. Khalaf, Friedel-Crafts Alkylation Chemistry, Marcel Dekker, New York, 1984. 

Resorting to alkylation chemistry again, 2-aminopyridine is condensed with the usual side chain halide to give diamine, 74. Alkylation of this with 2-chloromethylthiophene gives methapyrilene (75). Reaction with 2-chloromethyl-5-chlorothiophene affords the potent antihistamine chlorothen (76). ... 

It was concluded that the crosslinking reaction proceeded through initial alkylation of N-7 of adenine by the aziridine ring, followed by guanine N-7 alkylation by the epoxide (Figure 11.12). This seems inconsistent with Armstrong s earlier conclusions, but the very short oligonucleotides used by Saito et al. may influence the DNA alkylation chemistry. 

For a monograph, see Roberts, R.M. Khalaf, A.A. Friedel-Crafts Alkylation Chemistry Marcel Dekker NY, 1984. For a treatise on Friedel-Crafts reactions in general, see Olah, G.A. Friedel-Crafts and Related Reactions Wiley NY, 1963-1965. Volume 1 covers general aspects, such as catalyst activity, intermediate complexes, and so on. Volume 2 covers alkylation and related reactions. In this volume the various reagents are treated by the indicated authors as follows alkenes and alkanes, Patinkin, S.H. Friedman, B.S. p. 1 ... 

Madsen and co-workers have reported an important extension to the amine alkylation chemistry, in which oxidation takes place to give the amide product [13]. A ruthenium NHC complex is formed in situ by the reaction of [RuCl Ccod)] with a phosphine and an imidazolium salt in the presence of base. Rather than returning the borrowed hydrogen, the catalyst expels two equivalents of H. For example, alcohol 31 and benzylamine 27 undergo an oxidative coupling to give amide 32 in good isolated yield (Scheme 11.7). 

Dithionite-mediated reductive activation of mitomycin C has been employed in the study of its DNA alkylation chemistry.6,63 However, dithionite activated mitomycin C possesses different DNA alkylation properties than that activated by catalytic hydrogenation and enzymatic reduction. We postulated that a new alkylating species is produced by dithionite reductive activation resulting in different reactivity than the iminium methide species. To investigate dithionite-mediated reductive activation further, we treated 13 C-labeled analogues of WV-15 with dithionite and carried out spectral and product studies. 

Haldor Topspe s fixed-bed alkylation (FBA ) technology is a compromise between liquid and solid acid-based processes. It applies a supported liquid-phase catalyst in which liquid triflic (trifluoromethanesulfonic) acid is supported on a porous material (206,241). The acid in the bed is concentrated in a well-defined catalyst zone, in which all the alkylation chemistry takes place at the upstream... 

Samyn B., Hardeman K., Van der Eycken J., and Van Beeumen J. (2000), Applicability of the alkylation chemistry for chemical C-terminal protein sequence analysis, Anal. Chem. 72, 1389-1399. 

An aliphatic metal-carbon sigma bond, e. g., M-CH3, affords a fairly small C chemical shift, sometimes at negative d values. The relatively rare r allyl derivative, PdCl(q allyl)(PHOX), 61 [61], which is related to allylic alkylation chemistry, shows... 

G. A. Olah, ed., Friedel-Crafts and Related Reactions, Vols. 1-1V, Wiley-Interscience, New York, 1962-1964. R. M. Roberts and A. A. Khalaf, Friedel-Crafts Alkylation Chemistry, Marcel Dekker, New York, 1984. 

Kranz, K., 2003, Alkylation chemistry. Mechanisms, operating variables, and olefin interactions, http //www.stratco. dupont.com/alk/pdf/alkylation chemistry 2003.pdf (last visited February 2006)... 

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