For Campus Prearrival Information <click here> For a PDF of the 2015 Program Materials <click here> For ALL Abstracts [1-220] in sequential order <click here> For ALL Authors of the Lecture and Poster Presentations <click here>
A variety of carboxamidoximes (2), prepared from carbonitriles with NH2OH, could react with benzenesulfonyl chlorides (TsCl or o-NsCl) and DIPEA to form N-substituted cyanamides (3) in very good yields. The benzenesulfonyl chlorides promoted Tiemann rearrangement of carboxamidoximes (2) is readily amenable for the synthesis of a wide variety of cyanamide derivatives in multi-gram scales from carbonitriles.1 Acidic hydrolysis of the N-substituted cyanamides (3) afforded the corresponding N-monosubstituted ureas (4) in good yields. The preparation of the N-monosubstituted ureas (4) could also be accomplished in a one-pot fashion effectively from carbonitriles (2) with comparable yields.2 N-Alkyl-N’-arylguanidines (5) could be obtained from the reaction of N-arylcyanamides (3) with various primary and secondary alkylamines, under the catalysis of CuI and Xantphos in DMF. This methodology provides a direct access to versatile N,N’-disubstituted guanidine derivatives (5) from previously described N-arylcyanamides (3).3 The application of N-substituted cyanamides (3) toward the synthesis of various heterocycles, including benzimidazoles, benzoxazoles, and quinazolinones, has also been demonstrated.