1997 hydroxylation, hydroboration, phosphorylation, silylation

hydroxylation, hydroboration, phosphorylation, silylationO 0275

13 - 046N-Halocarbamate Salts Lead to More Efficient Catalytic AsymmetricAminohydroxylation. — Better enantioselectivity and convenientdeprotection make the sodium salt of N-chlorocarbamates (cf. (II)) theoxidant/nitrogen source of choice for the osmium/cinchona alkaloid catalyzedasymmetric aminohydroxylation of olefins. Using the corresponding smallerethyl carbamate the reaction is superior in terms of rate, enantioselectivity andyield. But despite the greater effectiveness of this reagent, the benzyl analogueis preferred because it can be cleaved easily by hydrogenolysis. This methodsimplifies the synthesis of a variety of compounds such as unnatural amino acidsand other pharmacologically important compounds. — (LI, G.; ANGERT,H. H.; SHARPLES, K. B.; Angew. Chem. 108 (1996) 23-24, 2995-2999; Dep.Chem., Scripps Res. Inst., La Jolla, CA 92037, USA; DE)

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