p -Iodotoluene二氟乙烯(p -Tol-IF 2)已被发现是一种一般用于有效地引入各种含氧官能团包括甲苯磺酰氧基,甲磺酰氧基,乙酰氧基,磷酰甲氧基,乙氧基和异丙氧基在α位的试剂β-二羰基化合物。通过使用对-碘甲苯二氟化物和各种含氧亲核化合物如对甲苯磺酸,甲磺酸,乙酸,磷酸二苯酯,甲醇,乙醇和丙-2-醇的组合试剂,可以轻松实现这些转化。分别在温和的条件下。并且,原位生成的高价碘(III)物种通过在这种转化中,对-碘甲苯二氟化物与相应的含氧亲核试剂之间的配体交换被认为是真正的氧化剂。
A novel route to 4-oxy/thio substituted-1H-pyrazol-5(4H)-ones via efficient cross-Claisen condensation
作者:R. Venkat Ragavan、V. Vijayakumar
DOI:10.1002/jhet.558
日期:2011.3
α‐Oxy/thio substitutedβ‐ketoesters were synthesized through an efficient cross‐Claisen condensation of oxy/thio substituted acetic acid ethyl esters with acid chlorides, which in turn converted in situ into 4‐oxy/thio substituted‐1H‐pyrazol‐5(4H)‐ones by the addition of hydrazine and its derivatives. This method has been found to be extremely fast, general, and useful toward the synthesis of inaccessible