Carbamates thiocarbamates

Yu, K., J. Krol, and M. Balogh (2003). A fully automated LC/MS method development and quantification protocol targeting 52 carbamates, thiocarbamates, and phenylureas. Anal. Chem., 75(16) 4103—4112. 

Coupling of a benzoic acid derivative under basic conditions is achieved with alkyl iodides," alkyl chlorides,dimethyl sulfate, or (l,1-dihydroperfluoroalkyl)phenyliodonium triflates. Common bases used arc potassium carbonate or sodium hydroxide (with phase-transfer catalyst). " Again, employing acid chlorides " - or anhydrides, " is the method of choice. The reaction can be performed without further activation, " " but in most cases the transformation takes place in the presence of the usual bases, triethylamine - " or pyridine " " " " " [in some cases 4-(dimethylamino)pyridine is added " ]. In a similar manner carbamates. thiocarbamates, " or thiocarbonates are synthesized. Perfluoropropcn-2-ol... 

Therefore, 1-chloroalkyl carbonates have been proposed as new acylating agents and thus are valuable precursors to carbamates, thiocarbamates and unsymmetrical ureas as outlined in section 3-3, this volume. 

Carbamates Thiocarbamates Dithi ocarbamates Triazoles s-Triazines... 

Carbamates Methyl carbamates Thiocarbamates 5xl02- 2 5x10-50 Highly polar enhanced solubility reduced adsorption compared with organochlorines... 

Dimethyl sulphoxide Naphthas Special solvents Carbamate, thiocarbamate Steam-cracked Cg - C7 aromatics... 

Various heterocycles 860 can be synthesized by the treatment of unsaturated aryl amides, carbamates, thiocarbamates and ureas 859 with IBX (Scheme 3.343) [1176,1177]. The mechanism of this reaction has been investigated in detail [1178]. On the basis of solvent effects and D-labeling studies, it was proposed that the IBX-mediated cyclization of anilides in THF involves an initial single-electron transfer (SET) to a THF-IBX complex followed by deprotonation, radical cyclization and concluding termination by hydrogen abstraction from THF [1178]. A similar IBX-mediated cyclization has been applied in the synthetic protocol for the stereoselective preparation of amino sugars [1179]. 

---