A New Synthesis of Imidazolidin-2-ones via Pd-Catalyzed Carboamination of N-Allylureas
摘要:
A new strategy for the preparation of substituted imidazolidin-2-ones in two steps from readily available N-allylamines is described. Addition of the amine starting materials to isocyanates affords N-allylureas, which are converted to imidazolidin-2-one products with generation of two bonds and up to two stereocenters when treated with aryl bromides and catalytic amounts of Pd-2(dba)(3)/Xantphos in the presence of (NaOBu)-Bu-t.
Catalytic hydration of cyanamides with phosphinous acid-based ruthenium(<scp>ii</scp>) and osmium(<scp>ii</scp>) complexes: scope and mechanistic insights
phosphinous acid-based complexes [MCl2(η6-p-cymene)(PMe2OH)] (M = Ru (1), Os (2)) as catalysts. The reactions proceeded cleanly under mild conditions (40–70 °C), in the absence of any additive, employing low metal loadings (1 mol%) and water as the sole solvent. In almost all the cases, the osmiumcomplex 2 featured a superior reactivity in comparison to that of its ruthenium counterpart 1. In addition
通过使用水合相应的氰胺R 1 R 2 NC N成功地完成了多种脲R 1 R 2 NC(O)NH 2的合成(R 1和R 2 =烷基,芳基或H; 26个实例)的三价膦酸基配合物[的MC1 2(η 6 - p -cymene)(PME 2 OH)](M =茹(1),锇(2))作为催化剂。反应在温和的条件下(40-70°C)干净进行,没有任何添加剂,使用低金属负载量(1 mol%)和水作为唯一溶剂。在几乎所有情况下,complex配合物2的反应活性都比钌配合物1高。另外,对于两种催化剂,氰酰胺底物水合所观察到的反应速率明显快于涉及传统脂族和芳族腈的反应速率。计算研究使我们能够合理化所有这些趋势。因此,计算表明存在直接与碳原子相连的氮原子当与金属中心配位时,N键通过感应效应使腈碳电子减少,从而促进次膦酸配体的OH基团对该碳的分子内亲核攻击。另一方面,Os对Ru的较高反应性似乎与初始金属环上较低的环应
Functionalized Cyclopentenones and an Oxime Ether as Antimicrobial Agents
作者:Rafael F. A. Gomes、Vera M. S. Isca、Késsia Andrade、Patrícia Rijo、Carlos A. M. Afonso
DOI:10.1002/cmdc.202100369
日期:2021.9.16
naturally occurring cyclopentenones, such as palmenones and nigrosporiones, exhibit antimicrobial activity. Herein we describe the antimicrobial activity of cyclopentenones and derivatives that can be easily accessed from biomass derivatives furfural and 5-hydroxymethylfurfural. Upon screening a range of functionalized trans-diamino-cyclopentenones (DCPs) and δ-lactone-fused cyclopentenones (LCPs), an oxime
Synthesis of Polycyclic Nitrogen Heterocycles via Cascade Pd-Catalyzed Alkene Carboamination/Diels–Alder Reactions
作者:Derick R. White、John P. Wolfe
DOI:10.1021/acs.orglett.5b00896
日期:2015.5.15
Cascade Pd-catalyzed alkenecarboamination/Diels–Alder reactions between bromodienes and amines bearing two pendant alkenes are described. These transformations generate 4 bonds, 3 rings, and 3–5 stereocenters to afford polycyclic nitrogen heterocycles with high diastereoselectivity.
Tandem hydroformylation–hydrazone formation–Fischer indole synthesis: a novel approach to tryptamides
作者:Axel M. Schmidt、Peter Eilbracht
DOI:10.1039/b503396a
日期:——
A novelone-potsynthesis of indole systems via tandem hydroformylation-hydrazone formation-Fischer indolization starting from allylic amides and aryl hydrazines is described. This tandem procedure directly leads to biologically interesting tryptamides and analogues.
Synthesis of Cyclic Guanidines via Pd-Catalyzed Alkene Carboamination
作者:Blane P. Zavesky、Nicholas R. Babij、Jonathan A. Fritz、John P. Wolfe
DOI:10.1021/ol402377y
日期:2013.11
A new approach to the synthesis of substituted 5-membered cyclic guanidines is described. Palladium-catalyzed alkene carboamination reactions between acyclic N-allyl guanidines and aryl or alkenylhalides provide these products in good yield. This method allows access to a number of different cyclic guanidine derivatives in only two steps from readily available allylic amines.