Metal-free oxidative decarbonylative alkylation of chromones using aliphatic aldehydes
作者:Rongzhen Chen、Jin-Tao Yu、Jiang Cheng
DOI:10.1039/c8ob00720a
日期:——
A decarbonylative alkylation of chromones via radical conjugate addition under metal-free conditions was developed using aliphaticaldehydes as alkylating reagents. A series of 2-tertiary, secondary, and even primary alkylated chromanones were obtained in moderate to excellent yields.
Catalytic asymmetric conjugate addition of Grignard reagents to chromones
作者:Carlos Vila、Valentín Hornillos、Martín Fañanás-Mastral、Ben L. Feringa
DOI:10.1039/c3cc43105c
日期:——
highly regio- and enantioselective copper catalysed direct conjugateaddition of Grignard reagents to chromones has been developed taking advantage of the reduced reactivity of the resulting magnesium enolates. This methodology tolerates a broad scope of alkyl Grignards including secondary alkyl magnesium reagents as well as functionalised chromones.
Tin-free radical reactions under minimal solvent conditions for the synthesis of substituted chromones and coumarins
作者:Jake R. Zimmerman、Madhuri Manpadi、Russell Spatney
DOI:10.1039/c1gc15775b
日期:——
An alkyltin-free radical methodology carried out under minimal solvent conditions is presented. This free radical addition process allows for the preparation of a variety of substrates, including substituted chromones and coumarins. This method is high yielding, conducted at ambient temperature and, in nearly all instances, classical purification techniques such as chromatography are not needed.
TMSOTf-Promoted Addition of Alkynes to Aldehydes: A Novel Synthesis of Chroman-4-ones
作者:Ji Yeon Park、Punna Reddy Ullapu、Hyunah Choo、Jae Kyun Lee、Sun-Joon Min、Ae Nim Pae、Youseung Kim、Du-Jong Baek、Yong Seo Cho
DOI:10.1002/ejoc.200800782
日期:2008.11
A novel synthetic method to prepare chalcones 2 and chroman-4-ones 3 by TMSOTf-promotedaddition of alkynes 1 to various aldehydes has been developed. The ratios of chalcones 2, chroman-4-ones 3 and hydrated products 4 varied depending upon the substituents R (nBu, phenyl, H and TMS) on the alkynes 1. We also describe the transformation of the chalcones 2 to the corresponding chroman-4-ones 3 under
Palladium-Catalyzed Dehydrogenation/Oxidative Cross-Coupling Sequence of β-Heteroatom-Substituted Ketones
作者:Youngtaek Moon、Daeil Kwon、Sungwoo Hong
DOI:10.1002/anie.201206610
日期:2012.11.5
Concise and selective: The title one‐pot sequence allows formation of the enone functionality and subsequent cross‐coupling. The process provides access to highly functionalized cyclic enolones and enaminones from readily accessible β‐heteroatom‐substituted cyclic ketones.