Trifluoroacetoxy-phenylselenation of nitroolefins regioselective preparation of nitroallylic alcohol derivatives and their use as multiple coupling reagents
作者:Dieter Seebach、Giorgio Calderari、Paul Knochel
DOI:10.1016/s0040-4020(01)96725-0
日期:1985.1
the products 16–34 of nitroallylation of various nucleophiles with substituted NPP-type reagents demonstrates the broad scope of these multiple coupling reagents. Due to the multitude of conversions of the nitro group, these reagents provide access to a great variety of structures without NO2 -substituents, cf. 2 and 3. The mechanism of the reaction of NPP-derivatives is discussed.
在以前的论文中已经表明,具有烯丙基离去基团的硝基烯烃2-硝基-2-丙烯-1-醇(NPP,1)的新戊酸酯可以用作通用的多重偶联试剂。本贡献描述了在烯丙基碳骨架的1-位和/或3-位取代的NPP类似物的制备。硝基脂族化学的标准方法很容易提供对称取代的衍生物,例如环己烯(7)和茚基(8),而非对称衍生物则不容易制备,例如苯基NPP 9。现在,通过将烯丙基新戊酰氧基引入硝基烯烃的区域选择性方法极大地改善了这种情况:在四步序列的第一步中,在硝基烯烃双键之间添加了苯基硒基和三氟乙酰氧基(10→11),然后,3 ·醚化(→14)。-用取代的NPP型试剂对各种亲核试剂进行硝基烯丙基化的产物16-34的区域选择性制备证明了这些多重偶联试剂的广泛应用范围。由于硝基的大量转化,这些试剂提供了无NO 2-取代基的各种结构的途径,请参见。参见图2和3。讨论了NPP衍生物的反应机理。