A new synthesis of imidazo [4,5-c] pyrazoles, obtained through cyclisation of 4-nitroso-5-alkylamino-pyrazoles, is described.
描述了通过4-亚硝基-5-烷基氨基-吡唑环化获得的咪唑并[4,5-c]吡唑的新合成方法。
Rhodium(II) Acetate‐Catalysed Cyclization of Pyrazol‐5‐amine and 1,3‐Diketone‐2‐diazo Compounds Using
<i>N</i>
,
<i>N</i>
‐Dimethylformamide as a Carbon‐Hydrogen Source: Access to Pyrazolo[3,4‐
<i>b</i>
]pyridines
4‐b]pyridines through a rhodium‐catalysed intermolecular cyclization of pyrazol‐5‐amine and cyclic 1,3‐diketone‐2‐diazo compounds, has been developed. A methyl carbon of N,N‐dimethylformamide (DMF) performed as a carbon‐hydrogen source for the construction of the pyridine ring. Various pyrazolo[3,4‐b]pyridine derivatives were obtained under mild conditions using air as the terminal oxidant.
已经开发了通过铑催化的吡唑-5-胺和环状1,3-二酮-2-重氮化合物与吡唑并[3,4- b ]吡啶的通道。N,N-二甲基甲酰胺(DMF)的甲基碳是构成吡啶环的碳氢源。在温和的条件下,使用空气作为末端氧化剂,可以得到各种吡唑并[3,4- b ]吡啶衍生物。
Enantioselective Synthesis of Dihydropyrazolo[3,4‐
<i>b</i>
]pyridin‐6‐ones via N‐Heterocyclic Carbene Catalyzed [3+3] Cycloaddition of
<i>α</i>
‐Bromoenals with 5‐Aminopyrazoles
作者:Yarui Li、Xiaoxia Huang、Jieyin He、Shiyong Peng、Jian Wang、Ming Lang
DOI:10.1002/adsc.202201335
日期:2023.2.21
An N-heterocycliccarbene (NHC) catalyzedasymmetric [3+3] annulation of α-bromoenals with 5-aminopyrazoles is described. Using the established methodology, a structurally diverse set of high value dihydropyrazolo[3,4-b]pyridine-6-ones were efficiently constructed in high yields (up to 99%) with excellent enantioselectivities (up to >99%). The easily available starting materials, broad substrate scope
描述了N-杂环卡宾 (NHC) 催化的α-溴烯醛与 5-氨基吡唑的不对称 [3+3] 环化反应。使用已建立的方法,以高产率(高达 99%)和出色的对映选择性(高达 >99%)有效地构建了一组结构多样的高价值二氢吡唑并[3,4- b ]吡啶-6-酮。易于获得的起始材料、广泛的底物范围、温和的反应条件、优异的产率和对映选择性使该策略对于吡唑并稠合吡啶酮衍生物的不对称构建具有吸引力。
Derivatives of 3-methyl-imidazo [4,5-c]pyrazole having therapeutic activity and a process for the preparation theref
申请人:CAMILLO CORVI S.p.A.
公开号:EP0190457A1
公开(公告)日:1986-08-13
The present invention concerns novel derivatives of 3-methyl-imidazo [4,5-c] pyrazole of formula
Said compounds have therapeutical activity, in particular said compounds are endowed with an intense CNS depressant activity. The invention furthermore concerns a process for preparing the compounds of formula (I).
developed for the first divergentsynthesis of pyrazolo[1,5-a]quinazolines through a [5 + 1] annulation reaction exclusively. The one-pot procedure is recognized for its broad substrate scope, functional group tolerance, and high atom economy. Mechanistic studies reveal the reaction pathway, addressing current limitations. Notably, this catalytic transition metal-assisted tandem annulation smoothly proceeds
开发了 Rh( III ) 催化的 C-H 活化/环化级联,用于仅通过 [5 + 1] 成环反应首次不同地合成吡唑并[1,5- a ]喹唑啉。一锅法因其广泛的底物范围、官能团耐受性和高原子经济性而受到认可。机理研究揭示了反应途径,解决了当前的局限性。值得注意的是,这种催化过渡金属辅助的串联环化通过取代的苯基-1H-吡唑-5-胺与炔酯或酰胺的反应顺利进行,其中单环碳由炔酸酯结构单元提供。这种转变凸显了过渡金属催化方法合成多种吡唑并[1,5- a ]喹唑啉骨架的潜力。