A new [4 + 2] type cyclocondensation was developed to prepare 3,5- and poly-substituted phenols using aryl ketoesters and ynones as the starting materials; Various substrates, such as aryl-, heteroaryl ketoesters and aryl-, vinyl-, alkyl substituted ynones, were employed. In addition, extending the substrate scope to benzoyl acetone provided 3,4,5-trisubstituted phenols.
A new strategy for the synthesis of 3,5-disubstituted phenols is established through one-pot Robinson annulation of α,β-unsaturated ketones with α-fluoro-β-ketoesters followed by in situ dehydrofluorination and tautomerization. This method has been extended to the synthesis of polysubstituted phenols and applied in the preparation of biologically active compounds.
Investigation of Alkyne Regioselectivity in the Ni-Catalyzed Benzannulation of Cyclobutenones
作者:Timo Stalling、Wesley R. R. Harker、Anne-Laure Auvinet、Erik J. Cornel、Joseph P. A. Harrity
DOI:10.1002/chem.201405863
日期:2015.2.2
A Ni‐catalyzed benzannulationreaction of cyclobutenones and alkynes provides a rapid synthesis of heavily substituted phenols. The regioselectivity of this reaction can be modulated by variation of substituents on the alkyne. Though the incorporation of Lewis basic donors provides modest selectivities, the use of aryl substituents can provide high levels of regiocontrol. Finally, alkynylboronates