730-18-7Relevant academic research and scientific papers
Catalytic substitution/cyclization sequences of: O -substituted Isocyanates: Synthesis of 1-alkoxybenzimidazolones and 1-alkoxy-3,4-dihydroquinazolin-2(1 H)-ones
Wang, Qiang,An, Jing,Alper, Howard,Xiao, Wen-Jing,Beauchemin, André M.
supporting information, p. 13055 - 13058 (2017/12/15)
O-Substituted isocyanates (O-isocyanates) have rarely been used in organic synthesis, given their tendency to undergo side reactions (e.g., trimerization). Herein, we show that masked (blocked) O-isocyanate precursors allow one-pot or cascade reaction sequences featuring base-catalyzed substitution with 2-iodoanilines and 2-iodobenzylamines followed by copper-catalyzed cyclization, to form benzimidazolones and 3,4-dihydroquinazolin-2(1H)-ones. This work shows that O-isocyanates can serve as efficient building blocks for the synthesis of hydroxylamine-containing heterocycles.
Microbial Iron Chelators: Total Synthesis of Aerobactin and Its Constiruent Amino Acid, N6-Acetyl-N6-hydroxylysine
Maurer, Peter J.,Miller, Marvin J.
, p. 3096 - 3101 (2007/10/02)
The synthesis of the natural ferric ionophore (-)-aerobactin (1) and of its constituent amino acid N6-acetyl-N6-hydroxylysine (2) is described.The benzyl hydroxamates * and ( were subjected to triphenylphosphine-diethyl azodicarboxylate-mediated alkylations with the ε-hydroxynorleucine derivative 7a.While * gave a complex mixture with predominant carbonyl O-alkylation, 9 was cleanly N-alkylated to yield 14.Compounds 10a,b were prepared by direct alkylation of 8 with bromides 15a,b which gave predominant N-alkylation.Hydrogenation of (D,L)-10a yielded (D,L)-N-6- acetyl-N6-hydroxylysine (2).Optically active 10b, prepared from (L)-ε-hydroxynorleucine, was α-N deprotected and coupled with anhydromethylenecitryl chloride (18) to yield 19, which was deprotected in two steps to yield (-)-aerobactin (1).
