Amine-promoted cyclocondensation of highly substituted aromatic nitrile oxides with diketones
作者:Jeffrey W Bode、Yoshifumi Hachisu、Tomoo Matsuura、Keisuke Suzuki
DOI:10.1016/s0040-4039(03)00614-2
日期:2003.4
Base-promoted cyclocondensation of hindered nitrile oxides and cyclic diketones affords highly functionalized, sterically-encumbered isoxazole products in good yield. The mild reaction conditions (NEt3, EtOH) are tolerant to a wide variety of functionality and permit the preparation of precursors to complex polycycles typically inaccessible via direct, intermolecular carboncarbon bond forming reactions
碱促进的受阻腈和环二酮的环缩合反应可提供高官能度,空间受限的异恶唑产物,收率很高。温和的反应条件(NEt 3,EtOH)可耐受多种功能,可制备复杂的多环化合物的前体,这些多环化合物通常无法通过直接的分子间碳碳键形成反应来获得。用催化量的胺进行环缩合反应的能力表明,烯醇酸铵作为关键的反应性物质的中介。由相应的肟方便,一步地制备结晶的,稳定的腈氧化物,增强了该方法制备功能化多环化合物的优势。