C stereospecific

Direct deprotonation/electrophile trapping of simple aziridines is also possible. Treatment of a range of N-Bus-protected terminal aziridines 265 with LTMP in the presence ofMe3SiCl in THF at-78 °C stereospecifically gave trans-a, 3-aziridinylsi-lanes 266 (Scheme 5.67) [96]. By increasing the reaction temperature (to 0 °C) it was also possible to a-silylate a (3-disubstituted aziridine one should note that attempted silylation of the analogous epoxide did not provide any of the desired product [81],... 

Due to the formal analogy to the classical Diels-Alder reaction, the mechanism of cyclic peroxide formation through cycloadditions of 1,3-dienes with O2 was considered for a long time to involve a concerted suprafacial [4 4- 2]-cycloaddition of a super-dienophile, namely a singlet oxygen to 1,3-dienic system In such a case, the concerted or almost concerted cycloaddition must be c -stereospecific and the stereochemical properties of the diene must be reflected in the three-dimensional structure of cyclic peroxide according to well-defined rules. Indeed, it was found in early stereochemical... 

Dioxiranes epoxidize different compounds with C=C stereospecifically and electrophili-cally (equation 25) in high yield (90-100%). 

Fig. 7. —Suggested Mechanisms for o/pho-Amylose Action, [a. Front-side displacement, where X and Y are substrate-binding groups, and N represents part of an imidazolium ring b. double displacement " and c. stereospecific hydration of a carbonium ion. ]...

Wickstrom, E. LeBec, C. Stereospecific Solid Phase Synthesis of Oligodeoxynucleoside Alkyl Phosphonates by Pentavalent Grignard Coupling. US Patent 5,703,223,1997. 

FIGURE 14,13. Mode of three-point attachment of prochiral methylaminomalonate to a chiral surface (a cobalt(III) complex), (a) Chemical formula of complex, (b) stereoview of complex, and (c) stereospecific decarboxylation. The carboxyl group that is hydrogen bonded to the complex is lost rather than the metal-bound carboxylate. 

Boter, H.L. and Van Dijk, C., Stereospecificity of hydrolytic enzymes on reaction with asymmetric organophosphorus compounds. The inhibition of acetylcholinesterase and butyrylcholinesterase by enantiomeric forms of sarin, Biochem. Pharmacol, 18, 2403, 1969. 

AA 24. Mohrig, J.R. Dabora, S.L. Foster, T.F. Schultz, S.C. Stereospecific Synthesis of 2-Deuterio-3-hydroxybutanoate Esters. Regiochemistry and Stereochemistry of Homogeneous Hydrogenation with Wilkinsons Catalyst J. Org. Chem. 1984, 49, 5179-5182... 

Lehmann, W.D. Theobald, N. Fischer, R. Heinrich, H.C. Stereospecificity of phenylalanine plasma kinetics and hydroxylation in man following oral application of a stable isotope-labelled pseudo-racemic mixture of l- and D-phenylalanine. Clinica. Chimica. Acta 1983, 128, 181-198. 

B.iv.c. Stereospecific Synthesis of C-Arylglycosides. The Pd- or Ni-catalyzed reaction of a-O-A -glycopyranoside (1) with arylmagnesium bromides has provided a- or /3-C-aryl-A -glycopyranosides, respectively, exhibiting 100% stereospecihcity in each case " (Scheme 19). A related stndy with aryltins and arylsilicates has also been pnblished.t ... 

Sita, L. R. Jayaratne, K. C. Stereospecific living polymerization of olefins by a novel Ziegler-Natta catalyst composition. U.S. Patent 6,579,998 B2 (University of Maryland), June 17, 2003. 

Gregoire, S. Dugat, D. Fournier, F. Gramain, J.-C. Tabet, J.-C. Stereospecific decompositions induced by low-energy collision-induced dissociation of MH ions of epimeric alkaloids. Rapid Comm. Mass Spectrom. 1995, 9, 9-12. 

THFsolvent effect reflects the coordinating ability CgHe > THF > C2H4CI2 of these solvents then a solvent such as benzene will compete with the diene for the monomeric nickel species. The allyl complex [Nil(/i -allyl)]2 also catalyses the dimerization of styrene at 0 °C stereospecifically to rra/7j-l,3-diphenylbut-l-ene. The rate law found for this reaction is ... 

Jaroch, S., Matsuoka, R.T., and Overman, L.E. (1999) Studies towards a total synthesis of sarains A-C. Stereospecific condensation of a.P Unsaturated esters with the phenyl oxazoline derivative of threonine. Tetrahedron Lett., 40,1273-1276. 

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