Group 14 elements phosgene

The oxidative carbonylation of amines to give ureas is at present one of the most attractive ways for synthesizing this very important class of carbonyl compounds via a phosgene-free approach. Ureas find extensive application as agrochemicals, dyes, antioxidants, resin precursors, synthetic intermediates (also for the production of carbamates and isocyanates), and HIV-inhibitors. Many transition metals (incuding Au [244], Co [248,253-255], Cu [242], Mn [249,256-258], Ni [259], Rh [246,247,260-262], Ru [224,260,263] and especially Pd [219,225,226,264-276], and, more recently, W [277-283]) as well as main-group elements (such as sulfur [284-286] and selenium [287— 292]) have been reported to promote the oxidative carbonylation of amines, usually under catalytic conditions. In some cases, carbamates and/or oxamides are formed as byproducts, thus lowering the selectivity of the process. 

It is remarkable how pooriy documented, on the whole, are the reactions of phosgene with the main group elements. There are very few classical studies of the reactivity of the elements with phosgene at low temperature, although the number of purely physical investigations are increasing. 

From the reactions of phosgene with fluorides of the main group elements... 

Reactions of phosgene with Group 4, Group 5 and Group 6 elements... 

Analysis of Reagent Purity H NMR, IR, elemental analysis. Preparative Methods the title reagent is prepared by the reaction of 2-(methylsulfonyl)-3-phenyl-2-propenyl alcohol and phosgene (eq 1). The alcohol is obtained from the corresponding allylic bromide by formate-catalyzed hydrolysis. The synthesis of the bromide involves the Cu(OAc)2-catalyzed addition of methanesulfonyl chloride to -methylstyrene followed by elimination of hydrogen chloride and subsequent free radical bromination of the methyl group (eq 1). ... 

Looking at Scheme 4.1, one can see that in chloroformylation, carhonylation, and chlorination reactions, phosgene reacts with nucleophilic groups Y-Z of monovalent type Z is always H, and Y is represented by the classical nucleophilic elements the reactivity (nucleophilicity) of the nucleophiles increases according to thiols <... 

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