A new and efficient CuI-catalyzed dominoKnoevenagel hetero-Diels-Alderreaction of 1-oxa-1,3-butadienes with terminal unactivated acetylenesas building blocks to afford pyrano[2,3- C]pyrazoleshas been developed. The products were obtained in good to high yieldsin most cases. Synthesis of polycyclic compounds in one-pot, witheasy workup, and mild reaction conditions are advantages of ourreported method
一种新型高效的 CuI 催化 1-oxa-1,3-丁二烯与末端未活化乙炔的多米诺 Knoevenagel 异-Diels-Alder 反应作为构建单元得到吡喃并 [2,3-C] 吡唑。在大多数情况下以良好到高产率获得产物。一锅法合成多环化合物、后处理容易、反应条件温和是我们报道的方法的优点。
Synthesis of 1H,7H,12bH-Pyrano[3′,4′: 5,6]pyrano[3,4-c][1]benzopyran-1-one via Domino Knoevenagel/Hetero-DielsAlder Reaction with Theoretical Investigations
intramolecular oxa‐DielsAlder reaction of 2‐(prop‐2‐yn‐1‐yloxy)benzaldehydes as unactivated terminal alkynes with 4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one is described. The reaction proceeds with remarkable chemoselectivity to yield pyranones 3 (Scheme 1). A theoretical investigation of the reaction in terms of HOMOLUMO interactions in the gas phase is also reported. The reaction could be regarded as an in
描述了CuI催化的分子内oxa Diels - Al 2-(prop-2-yn-1-yloxy)苯甲醛作为未活化的末端炔烃与4-hydroxy-6-methyl-2 H -pyran-2-one的Alder反应。反应以显着的化学选择性进行,得到吡喃酮3(方案1)。反应在HOMO方面的理论探讨还报道在气相中LUMO的相互作用。该反应可以被认为是逆电子点播狄尔斯阿尔德环加成。理论结果与实验证据高度吻合。