Carbamic acid synthesis

Addition of Carbamic Acids Synthesis of Vinylic Carbamates and Ureas... 

Recently, Scialdone and colleagues have employed phosgenated />-nitrophenyl(poly-styrene) ketoxime (Phoxime, 76) resin in the synthesis (via 77 and 78) of acyclic and heterocyclic amino-acid-derived ureas 79 too (Scheme 42). Resin 75 was first reacted with an amino acid and TMSCl in pyridine, and the resulting carbamate acid resin 77 was then coupled with an amine under standard carbodiimide protocol (HOBt/DIC in DMF) to obtain the carbamate amide resin 79. 

The Chemistry of N-C02 Bonds Synthesis of Carbamic Acids and Their Derivatives, Isocyanates, and Ureas... 

All of these compounds, whether alkylammonium, metal and p-block carbamates, are potential carriers or sources of carbamic groups, and can be used in the synthesis of organic carbamates [6] if the transfer of the RR NC02 moiety to a suitable organic substrate is accomplished [6, 7]. Moreover, alkylammonium, metal and p-block carbamates, as well as carbamic acid esters, are also potential... 

Usually, the traditional routes to the synthesis of carbamic acid esters, isocyanates and ureas start from the toxic compound phosgene [10]. Consequently, the ability to synthesize these compounds from ubiquitous, cheap and safe C02, as an alternative starting material to phosgene, represents an appealing and highly eco-friendly variation to the conventional protocols which have in the past been based on phosgenation. Moreover, it also provides an attractive answer to the current widespread requests for environmental protection [11]. 

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