Flavones are important natural products with diverse biological activities. In this study, a novel procedure for the carbonylative synthesis of flavones has been developed by using simple phenols and internal alkynes as the substrates. Various flavones were isolated in moderate to good yields with excellent regioselectivity and functional group tolerance by using an iridium catalyst system. Notably
Carbopalladation of Nitriles: Synthesis of 3,4-Disubstituted 2-Aminonaphthalenes and 1,3-Benzoxazine Derivatives by the Palladium-Catalyzed Annulation of Alkynes by (2-Iodophenyl)acetonitrile
作者:Qingping Tian、Alexandre A. Pletnev、Richard C. Larock
DOI:10.1021/jo026229+
日期:2003.1.1
studied. The annulation of certain hindered propargylic alcohols affords 1,3-benzoxazinederivatives, rather than the expected 2-aminonaphthalenes. The involvement of trialkylamine bases in the formation of these heterocyclic compounds has been established. A proposed mechanism for the synthesis of 1,3-benzoxazinederivatives involves the formation of the expected 2-amino-3-(1-hydroxyalkyl)naphthalenes
Novel [1,5] Sigmatropic Rearrangements of Cyclohexadienones Generated from Fischer Carbene Complexes. A New Strategy for Installing the C-20 Angular Ethyl Group in Aspidospermidine Alkaloids
作者:John F. Quinn、Mary Ellen Bos、William D. Wulff
DOI:10.1021/ol990063q
日期:1999.7.1
here the first examples of a [1,5] sigmatropicrearrangement in a 4a-alkyl-4a-hydrocarbazol-4-one to yield a 3-alkylcarbazol-4-one with a re-aromatized indole nucleus. The reaction of 1-methyl-3-substituted-indole-2-carbene complexes 1 with terminal alkynes yields 3,4a-dialkyl-1-methoxy-9-methylcarbazol-4-ones 2. These 4a-substituted carbazolones thermallyrearrange to cleanly give the more highly aromatic
Tetraphenylcyclopentadienyl rhodium complexes in stoichiometric and catalytic CH functionalization
作者:David L. Davies、Charles E. Ellul、Kuldip Singh
DOI:10.1016/j.jorganchem.2018.09.005
日期:2019.1
[RhCl2(η-C5Ph4H)]2 for stoichiometric and catalytic CH functionalization has been evaluated. For the substrates studied, CH activation, alkyne insertion and CN reductiveelimination are all possible at roomtemperature, similar to corresponding reactions with [RhCl2(η-C5Me5)]2. The tetraphenylcyclopentadienyl ligand shows promise for controlling regioselectivity in catalytic CH functionalization.
Oxidative annulations via double CH bond cleavages: Approach to quinoline derivatives
作者:Zhenghui Liu、Shien Guo、Peng Wang、Zhenzhong Yan、Tiancheng Mu
DOI:10.1002/aoc.6156
日期:2021.4
system via oxidative annulations was proposed. A systematic exploration was completed. All kinds of reaction parameters were determined. And 55 kinds of target molecules were obtained with moderate to high yields. Combination of double oxidants made the conversion proceed smoothly. A clear reaction mechanism was put forward. Adjacent π systems might provide assistance for realizing the activation of relatively