Kagan’s method

Substrate Modena s method Kagan s method U Kagan s method lU Kagan s method llU... 

Substrate Modena s method0 Kagan s method lh Kagan s method IIc Kagan s method IlU... 

Kaganer s method (S3) uses an equation that applies especially in the range of p/po from 10 to 3 X 10 ... 

Of several procedures for the stereoselective oxidation of sulfides using organometallic complexes, two adaptations of Kagan s original process have gained prominence. In the first method the diol (36) is reacted with Ti(0 Pr)4 to form the catalyst. With cumyl hydroperoxide as the stoichiometric oxidant, methyl para-tolyl sulfide was converted into the optically active sulfoxide in 42 % yield (98 % ee)[109]. 

TABLE 27. Results of the titanium-catalyzed stoichiometric enantioselective sulfoxidation according to Kagan s and Modena s methods (yields are given and ee values are given in parentheses)... 

Kaganer modified Dubinin s method in order to calculate the surface area within micropores. He assumed that the adsorption potential of the sites is distributed according to a Gaussian function such that... 

This is the second important contribution of Kagan s group in the synthesis of chiral sulfoxides. The method was reported in 1989 for the synthesis of tert-butyl sulfoxides,90 and the full paper on the generalization of the method was published in 1991.86 The approach is based on the synthesis and use of an o.p. cyclic sulfite in the synthesis of various sulfoxides by two successive condensations of two organometallic reagents, RjM and R2M. Thus, the sulfoxides are produced in three separate steps the formation of cyclic sulfite, synthesis of sulfinate esters, and transformation of sulfinates to chiral sulfoxides. 

Kagan s sulfite, the method has the advantage of regioselectivity, but the limitation of producing tert-butyl or aryl phenyl sulfoxides. 

Kagan et al. s method, confirming how tailoring experimental conditions for this class of multicomponent catalytic reactions is extremely important. 

Equation (9.15) is similar to equation (9.10), Dubinin s equation. A plot of log IT versus [log(Po/ )] will yield a straight line with an intercept of loglT from which the surface area can be calculated by equation (4.13). The linear range of these plots are usually at very low relative pressures, less than 10 . Kaganer showed excellent agreement between surface areas measured using equation (9.15) and the BET method on a variety of adsorbate-adsorbent systems. 

Mikhail, Brunauer, and Bodor proposed an extension of deBoer s r-method for the analysis of micropores which offers several advantages. These include the ability to obtain the micropore volume, surface, and their distributions from one experimental isotherm. Data for the MP (micropore analysis) method need not be measured at the very low pressures needed for the Dubinin and Kaganer theories. The method... 

Jensen, S. A., Vrhovski, B., and Weiss, A. S. (2000). Domain 26 of tropoelastin plays a dominant role in association by coacervation./. Biol. Chem. 275, 28449-28454. Kagan, H. M., and Sullivan, K. A. (1982). Lysyl oxidase Preparation and role in elastin biosynthesis. Methods Enzymol. 82, 637-650. 

The first samples were obtained by resolution.191193 Because the last step in the synthesis of the racemate is the oxidation of the sulfide to the sulfoxide,194-198 this has been modified to provide the S-isomer (Scheme 31.15). This is achieved by the Kagan method, which is a variation of the Sharpless epoxidation (see Chapter 9).199 200... 

Jacques, J., Gros, C. and Bourcier, S. (1977) in H.B. Kagan (Ed.), Absolute Configurations of 6000 Selected Compounds with One Asymmetric Carbon Atom, Stereochemistry—Fundamentals and Methods, Vol. 4, Georg Thieme, Stuttgart. 

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