C− H Activation with Elemental Sulfur: Synthesis of Cyclic Thioureas from Formaldehyde Aminals and S8

…, S Gupta, J Brownie, S Tajammul…

Index: Denk, Michael K.; Gupta, Shilpi; Brownie, John; Tajammul, Sabiha; Lough, Alan J. Chemistry - A European Journal, 2001 , vol. 7, # 20 p. 4477 - 4486

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Citation Number: 45

Abstract

Abstract The C− H activation of cyclic formaldehyde aminals LCH 2 (L= RN-CH 2 CH 2 CH 2- NR and RNCH 2 CH 2 NR, R= Me, Et, iPr, tBu, or Ph) with S 8 proceeds at unusually low temperatures (T< 160 C) and results in the formation of the respective thioureas LC= S and H 2 S. The reaction constitutes a new, solvent-free method for the synthesis of thioureas that eliminates the toxic and highly flammable CS 2. For R= tBu, the ionic carbenium ...