Trifluoroacetic Acid-Mediated Hydroarylation: Synthesis of Dihydrocoumarins and Dihydroquinolones
摘要:
Trifluoroacetic acid mediates the hydroarylation of alkenes to afford dihydrocoumarins and dihydroquinolones in good yield. Intermolecular hydroarylation of cinnamic acids by phenols is particularly facile, which leads to the conclusion that previous reports of palladium-catalyzed hydroarylation of cinnamic acids in trifluoroacetic acid are erroneous.
Hexafluoroisopropanol and Acetyl Chloride Promoted Catalytic Hydroarylation with Phenols
作者:Sudeshna Roy、Hashim F. Motiwala、Karl M. Koshlap、Jeffrey Aubé
DOI:10.1002/ejoc.201701256
日期:2018.1.23
HFIP facilitates the mild catalytic hydroarylation of phenols to provide dihydrocoumarins using sub‐stoichiometric amounts of acetylchloride as catalyst.
HFIP促进了酚的轻度催化加氢芳基化反应,从而使用亚化学计量的乙酰氯作为催化剂提供了二氢香豆素。
Reduction of Pyrrolyl- and Indolylamides with BH<sub>3</sub>·THF: Cyclodeoxygenation versus Deoxygenation
作者:Kelin Li、Jon A. Tunge
DOI:10.1021/jo801627z
日期:2008.11.7
Herein we report that borane reductions of acylpyrroles and acylindoles that contain a pendant phenol take two different paths. Acylpyrroles undergo a reductive cyclization to make unusual chromanyl pyrroles. Treatment of related acylindoles under identical conditions results in deoxygenation without cyclization. The results are interpreted in terms of relative rates of cyclization and reduction of intermediate carbenium ions, where cyclization of the indole-stablized carbenium ion is slower.
Stereochemical Control in the Reduction of 2-Chromanols
作者:Kelin Li、Kumar Vanka、Ward H. Thompson、Jon A. Tunge
DOI:10.1021/ol061727g
日期:2006.10.1
silane reductants and 2,4-trans-chromans using the smaller silane PhSiH(3). The stereochemical outcome has been rationalized on the basis of a Curtin-Hammett kinetic situation arising from hydride delivery to two different conformations of an intermediate oxocarbenium ion. This method provides a powerful way to control the relative stereochemistry of these substructures which are prevalent in bioactive
Trifluoroacetic Acid-Mediated Hydroarylation: Synthesis of Dihydrocoumarins and Dihydroquinolones
作者:Kelin Li、Lindsay N. Foresee、Jon A. Tunge
DOI:10.1021/jo0477650
日期:2005.4.1
Trifluoroacetic acid mediates the hydroarylation of alkenes to afford dihydrocoumarins and dihydroquinolones in good yield. Intermolecular hydroarylation of cinnamic acids by phenols is particularly facile, which leads to the conclusion that previous reports of palladium-catalyzed hydroarylation of cinnamic acids in trifluoroacetic acid are erroneous.