Isocyanides from diphosgene

An even higher density of functional groups can be achieved with 1,1-difiinc-tionalized isocyanides. a-Cyano-a-isocyanoalkanoates 1540 are synthesized as versatile synthons for the assembly of imidazoles 1543 by the loss of carbonate 1542 from intermediate 1541 [1178]. Dehydration of the corresponding formamides 1539 with diphosgene affords the 1-cyano-l-isocyanides 1540. 

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