An Experimental and Computational Approach to Understanding the Reactions of Acyl Nitroso Compounds in [4 + 2] Cycloadditions
作者:Duangduan Chaiyaveij、Andrei S. Batsanov、Mark A. Fox、Todd B. Marder、Andrew Whiting
DOI:10.1021/acs.joc.5b01470
日期:2015.10.2
Catalytic aerobic oxidation of phenyl hydroxycarbamate 1 and 1-hydroxy-3-phenylurea 2 using CuCl2 and 2-ethyl-2-oxazoline in methanol gave acyl nitroso species in situ, which were trapped in nitroso-Diels–Alder (NDA) reactions with various dienes to afford the corresponding cycloadducts in high yields (90–98%). Competing ene products were also present for dienes containing both alkene π-bonds and allylic
在甲醇中使用CuCl 2和2-乙基-2-恶唑啉催化好氧氧化苯基羟基氨基甲酸酯1和1-羟基-3-苯基脲2得到原位的酰基亚硝基物质,将其捕获在亚硝基-Diels-Alder(NDA)反应中。各种二烯以高产率(90-98%)提供相应的环加合物。竞争烯产品也存在于含有烯烃的π键和烯丙基σ-键二烯,和烯产率更高的1比2。手性异羟肟酸(R)-1-羟基-3-(1-苯基乙基脲)3的用途(在相同条件下)以高收率(97-99%)得到了NDA环加合物,没有2,3-二甲基-1,3-丁二烯的烯烃产物。从其他异羟肟酸类似物[RCONHOH(R = PhCH 2 4 ; Ph(CH 2)2 5 ; Ph(CH 2)3 6 ; Ph(CH 2)4 7 ; Ph 8 ; 2-吡啶基9 ; 3-吡啶基10使用高碘酸钠获得]用铜-氧化各种二烯而是导致从异羟肟酸可变NDA的产率(13-51%)1 - 10具有环己-1,3-二烯和2