Carbon Dioxide as a Carbonylating Agent in the Synthesis of 2-Oxazolidinones, 2-Oxazinones, and Cyclic Ureas: Scope and Limitations

Abstract

Carbon dioxide can be used as a convenient carbonylating agent in the synthesis of 2-oxazolidinones, 2-oxazinones, and cyclic ureas. The transient carbamate anion generated by treating a primary or secondary amine group in basic media can be activated with phosphorylating agents such as Diphenylphosphoryl azide (DPPA) and Diphenyl chlorophosphate (DPPCl) but also with other types of electrophiles such as SOCl(2), TsCl, or AcCl. The intramolecular trapping of the activated carbamate by a hydroxyl group leads to the formation of 2-oxazolidinones or 2-oxazinones in good to excellent yields. This methodology was successfully applied to the synthesis of cyclic ureas up to 7-membered rings from the corresponding diamines.

Synthesis and preclinical evaluation of [11C-carbonyl]PF-04457845 for neuroimaging of fatty acid amide hydrolase

“…Cyclotron produced [ 11 C]CO 2 is captured in solution by BEMP, forming a BEMP-[ 11 C]CO 2 adduct which rapidly exchanges with PPP forming a [ 11 C]carbamic salt that is then dehydrated to a mixed [ 11 C]anhydride (Scheme 2) [43]. The aromatic amine 3-APZ, present in 20-fold excess compared to PPP, then reacts with the anhydride to form the [ 11 C]urea bond.…”

Synthesis and nanostructure of [Mo(C 6 H 4 O 2 ) 3 ]·2(C 4 H 8 N 2 O) and the synthesis from 1,2-PDA to (C 4 H 8 N 2 O)

“…In fact, this sort of shuttling action has been proposed as part of the catalytic mechanism of a number of enzymes, [13][14][15] and is consistent with the proton conductivity properties of imidazole in the solid state where long H bonded chains are present. [16] Although the synthesize mechanism of C 4 H 8 N 2 O has been revealed with the catalyst of CeO 2 [17][18][19] , the catalytic of Mo-complex to synthesize imidazole ring with the reactants of 1,2-propanediamine (1,2-DPA) and CO 2 was rarely presented to date.…”

Acyclic and Cyclic Ureas (Update 2013)

“…[138] This reaction proceeds under mild conditions at temperatures between -40 8 8C and room temperature under an atmosphere of carbon dioxide. It is mediated by 1,1,3,3-tetramethyl-2-phenylguanidine as a base and diphenylphosphoryl azide as a phosphorylating agent.…”