2-Pyridones from Cyanoacetamides and Enecarbonyl Compounds: Application to the Synthesis of Nothapodytine B
摘要:
The condensation of an enone or enal with cyanoacetamide derivatives and t-BuOK furnishes either 3-eyano-2-pyridones or 3-unsubstituted-2-pyridones, depending on whether the reaction is carried out in the presence or in the absence Of O-2. In the first case, in situ oxidation of Michael-type intermediates takes place; in the second case, the products result from "decyanidative aromatization" of such intermediates. A one-step synthesis of 3-alkyl-2-pyridones has been devised on the basis of decyanative union of an enone/enal and a 2-alkyleyanoacetamide. The new reaction forms the centerpiece of an unusually concise synthesis of nothapodytine B (mappicine ketone).
We report a highly efficient and selective catalytic system, ABNO (9-azabicyclo-[3.3.1]nonane N-oxyl)/HNO3, for the aerobic oxidation of substituted furans to cis-2-ene-1,4-diones under mild reaction conditions using oxygen as the oxidant. The catalyst system is amenable to various substituted (mon-, di-, and tri-) furans and tolerates diverse functional groups, including cyano, nitro, naphthyl, ketone
我们报告了一种高效和选择性催化体系 ABNO (9-azabicyclo-[3.3.1] nonane N -oxyl)/HNO 3,用于将取代的呋喃有氧氧化为顺式-2-ene-1,4-二酮以氧气为氧化剂,反应条件温和。该催化剂体系适用于各种取代的(单-、二-和三-)呋喃,并耐受多种官能团,包括氰基、硝基、萘基、酮、酯、杂环,甚至甲酰基。基于对照和18个O标记实验,提出了氧化的可能机理。
Design and synthesis of furyl/thineyl pyrroloquinolones based on natural alkaloid perlolyrine, lead to the discovery of potent and selective PDE5 inhibitors
Based on perlolyrine (1), a natural alkaloid with weak PDE5 potency from the traditional Chinese aphrodisiac plant Tribulus terrestris L., a series alpha-substituted tetrahydro-beta-carboline (TH beta C) derivatives were synthesized via T(+)BF4(-)-mediated oxidative C-H functionalization of N-aryl TH beta Cs with diverse potassium trifluoroborates. Following Winterfeldt oxidation afforded the corresponding furyl/thienyl pyrroloquinolones, of which 5-ethylthiophene/ethylfuran derivatives 20a-b were identified as the most potent and selective PDE5 inhibitors. Among the enantiomers, (S)-20a and (S)-20b (IC50 = 0.52 and 0.39 nM) were found to be more effective than their (R)-antipode, display favorable pharmacokinetic profiles, exert in vitro vasorelaxant effects on the isolated thoracic aorta, and exhibit in vivo efficacy in the anesthetized rabbit erectile model. (C) 2018 Elsevier Masson SAS. All rights reserved.
2-Pyridones from Cyanoacetamides and Enecarbonyl Compounds: Application to the Synthesis of Nothapodytine B
作者:Lionel Carles、Kesavaram Narkunan、Sébastien Penlou、Laurence Rousset、Denis Bouchu、Marco A. Ciufolini
DOI:10.1021/jo025546d
日期:2002.6.1
The condensation of an enone or enal with cyanoacetamide derivatives and t-BuOK furnishes either 3-eyano-2-pyridones or 3-unsubstituted-2-pyridones, depending on whether the reaction is carried out in the presence or in the absence Of O-2. In the first case, in situ oxidation of Michael-type intermediates takes place; in the second case, the products result from "decyanidative aromatization" of such intermediates. A one-step synthesis of 3-alkyl-2-pyridones has been devised on the basis of decyanative union of an enone/enal and a 2-alkyleyanoacetamide. The new reaction forms the centerpiece of an unusually concise synthesis of nothapodytine B (mappicine ketone).