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Protecting group and solvent control of stereo- and chemoselectivity in glucal 3-carbamate amidoglycosylation.

ABSTRACT: In the Rh(2)(OAc)(4)-catalyzed amidoglycosylation of glucal 3-carbamates, anomeric stereoselectivity and the extent of competing C3-H oxidation depend on the 4O and 6O protecting groups. Acyclic protection permits high alpha-anomer selectivity with further improvement in less polar solvents, while electron-withdrawing protecting groups limit C3-oxidized byproducts. Stereocontrol and bifurcation between alkene insertion and C3-H oxidation reflect an interplay of conformational, stereoelectronic, and inductive factors.

SUBMITTER: Gupta R

PROVIDER: S-EPMC2684990 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature

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Protecting group and solvent control of stereo- and chemoselectivity in glucal 3-carbamate amidoglycosylation.

Gupta Ritu R Sogi Kimberly M KM Bernard Sarah E SE Decatur John D JD Rojas Christian M CM

Organic letters 20090401 7

In the Rh(2)(OAc)(4)-catalyzed amidoglycosylation of glucal 3-carbamates, anomeric stereoselectivity and the extent of competing C3-H oxidation depend on the 4O and 6O protecting groups. Acyclic protection permits high alpha-anomer selectivity with further improvement in less polar solvents, while electron-withdrawing protecting groups limit C3-oxidized byproducts. Stereocontrol and bifurcation between alkene insertion and C3-H oxidation reflect an interplay of conformational, stereoelectronic, ...[more]

PMID: 19254041

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