An operationally simple and convenient synthesis method toward a series of diverse spiro[4.4]thiadiazole derivatives via double [3 + 2] 1,3-dipolarcycloaddition of nitrilimines generated in situ from hydrazonyl chlorides with carbon disulfide has been achieved undermild reaction conditions.
Regioselective [3 + 2]-annulation of hydrazonyl chlorides with 1,3-dicarbonyl compounds for assembling of polysubstituted pyrazoles
作者:Kun Liu、Xinye Shang、Yuyu Cheng、Xiaoyong Chang、Pengfei Li、Wenjun Li
DOI:10.1039/c8ob02352b
日期:——
The facile approach to polysubstituted pyrazoles from hydrazonyl chlorides and 1,3-dicarbonyl compounds has been developed. Hydrazonyl chlorides reacted with N-phenyl-3-oxobutanamides smoothly to afford a series of polysubstituted pyrazoles in 67–98% yields via the [3 + 2]-cycloaddition.
The double 1,3-dipolar cycloaddition of allenoates with nitrilimines has been achieved under mild reaction conditions, affording a variety of spirobidihydropyrazoles in moderate to excellent yields with excellent diastereoselectivities. The reaction diastereoselectively constructs double dihydropyrazole moieties and two chiral centers including a spiro carbon center.
A [4 + 3] Annulation Reaction of aza-<i>o</i>-Quinone Methides with Arylcarbohydrazonoyl Chlorides for Synthesis of 2,3-Dihydro-1<i>H</i>-benzo[<i>e</i>][1,2,4]triazepines
An unprecedented [4 + 3] annulation reaction of aza-ortho-quinone methides with arylcarbohydrazonoyl chlorides has been achieved under mild conditions. The annulation underwent a sequential conjugate addition/intramolecular annulation/rearrangement, providing a useful method for the synthesis of biologically interesting 2,3-dihydro-1H-benzo[e][1,2,4]triazepine.
在温和的条件下,已完成了氮杂-邻苯醌甲基化物与芳基羰基肼基甲酰氯的前所未有的[4 + 3]环化反应。进行连续的共轭加成/分子内的成环/重排,为生物上有趣的2,3-二氢-1 H-苯并[ e ] [1,2,4]三氮杂卓合成提供了有用的方法。