A useful aminohalogenation reaction for the cyclization of O-alkynyl carbamates under copper catalysis has been developed. N-Halosuccinimides have used as a halogen source. The intramolecular C−N bond formation occurs selectively affording haloalkylidene substituted heterocycles. Just in case α,α-cyclohexyl-substituted propargyl carbamate, alkoxyhalogenation pathway was operative. mechanism two...

Mammalian cells acquire cholesterol, a critical membrane constituent, through multiple mechanisms. We synthesized mimics of cholesterol, fluorescent N-alkyl-3β-cholesterylamine-glutamic acids, that are rapidly incorporated into cellular plasma membranes compared with analogous cholesteryl amides, ethers, esters, carbamates, and a sitosterol analogue. This process was inhibited by ezetimibe, ind...

Reactions of(4S,5R)-1-(3,4-Dimethyl-2-oxo-5-phenylimidazolidine)carbonyl-isocyanate (4) with appropriate Baylis-Hillman adducts 5 gave the corresponding acyl carbamates 6,7 as equimolar diastereomeric mixtures. These mixtures were treated with DABCO, to afford with moderate diastereoselection easily separable [2-(3",4"-dimethyl-2"-oxo-5"-phenylimidazolidine-1-carboxamido)(aryl)methyl]acrylates ...

A palladium-catalyzed oxidative acylation of O-phenyl carbamates with a-oxocarboxylic acids via selective aromatic C H bond activation is described. This protocol represents the first ortho-acylation of phenol derivatives, and a catalytic amount of triflic acid additive is crucial for this transformation.