Selective Tsuji–Trost type C-allylation of hydrazones: a straightforward entry into 4,5-dihydropyrazoles
作者:El Hachemia El Mamouni、Martin Cattoen、Marie Cordier、Janine Cossy、Stellios Arseniyadis、Hocine Ilitki、Laurent El Kaïm
DOI:10.1039/c6cc08171a
日期:——
Tsuji–Trost typeC-allylation access to 4,5-dihydropyrazoles.
辻-トロスト型C-烯丙基化による4,5-二氢ピラ唑の合成方法。
Metal-Free Tandem Oxidative Cyclization for the Synthesis of 1,2-Dihydropyridazines and Pyrazoles
作者:Dongping Cheng、Yinqiang Shen、Ziliang Wu、Xiaoliang Xu、Jizhong Yan
DOI:10.1021/acs.joc.1c00020
日期:2021.7.2
disclosed to generate appealing β,γ-unsaturated hydrazones, which further undergo 5-exo-trig or 6-endo-trig cascade cyclization to give the respective 1,2-dihydropyridazines or pyrazoles selectively under metal-free conditions. The mechanisms of the coupling and subsequent cyclization are proposed.
在 2,3-二氯-5,6-二氰基-1,4-苯醌 (DDQ) 介导下,腙和 1,3-二芳基丙烯的新型氧化偶联已被公开,可生成有吸引力的 β,γ-不饱和腙,这进一步在无金属条件下进行5- exo -trig或6- end -trig级联环化,选择性地生成各自的1,2-二氢哒嗪或吡唑。提出了偶联和随后环化的机制。
N-Heterocyclic Carbene-Catalyzed Oxidative Annulations of α,β-Unsaturated Aldehydes with Hydrazones: Selective Synthesis of Optically Active 4,5-Dihydropyridazin-3-ones and Pyridazin-3-ones
A novel and efficient method for the highly enantioselective synthesis of chiral 4,5-dihydropyridazin-3-one derivatives has been developed based on the chiral N-heterocycliccarbene-catalyzed oxidative annulation between α,β-unsaturated aldehydes and hydrazones. Meanwhile, the selective synthesis of either 4,5-dihydropyridazin-3-ones or pyridazin-3-one derivatives from the same reactants has been achieved
The use of hydrazones for efficient mannich type coupling with aldehydes and secondary amines
作者:Valérie Atlan、Hugues Bienaymé、Laurent El Kaim、Adinath Majee
DOI:10.1039/b002750m
日期:——
The Mannich reaction of hydrazones originally limited to the
coupling of hydrazones with formaldehyde has been extended to a large
variety of aldehydes through appropriate selection of experimental
conditions; in conjunction with the Japp–Klingmann reaction, this
process provides an efficient synthetic tool for the formation of
carbon–carbon bonds.
A variety of pyrrolo[3,4-c]pyrazole derivatives from readily available aldehyde hydrazones and maleimides via direct oxidative coupling under radical cascade reaction have been reported. This method offers satisfactory chemical yields and good functional group compatibility. Moreover, this practical approach is catalyzed by CuCl utilizing air as the oxidant and some control experiments were performed
已经报道了在自由基级联反应下通过直接氧化偶合从易得的醛和马来酰亚胺得到的各种吡咯并[3,4- c ]吡唑衍生物。该方法提供令人满意的化学产率和良好的官能团相容性。此外,该实用方法是通过以空气为氧化剂的CuCl催化的,并进行了一些控制实验以阐明其机理。