Regioselective reduction of 2-perfluoroalkanoylcyclohexane-1,3-diones and their enamino derivatives
摘要:
Ionic hydrogenation of 2-perfluoroalkanoylcyclohexane-1,3-diones and their endocyclic enamino derivatives containing a secondary amino group by the action of triethylsilane in trifluoroacetic acid in the presence of a catalytic amount of lithium perchlorate involved regioselective reduction of the side-chain carbonyl group to hydroxy with formation of the corresponding hydroxy diketones and hydroxy amino ketones, respectively. Under analogous conditions endocyclic enamino derivatives possessing a tertiary amino group underwent deacylation to give enamino ketones.
Gold-Catalyzed Heterogeneous Aerobic Dehydrogenative Amination of α,β-Unsaturated Aldehydes to Enaminals
作者:Xiongjie Jin、Kazuya Yamaguchi、Noritaka Mizuno
DOI:10.1002/anie.201308260
日期:2014.1.7
octahedral molecular sieves OMS‐2 (Au/OMS‐2), dehydrogenativeamination of α,β‐unsaturated aldehydes with amines proceeded efficiently, with the corresponding enaminals isolated in moderate to high yields (50–97 %). The catalysis was truly heterogeneous, and Au/OMS‐2 could be reused. Furthermore, the formal Wacker‐type oxidation of α,β‐unsaturated aldehydes to enaminones has been realized.
An efficient method for <i>retro</i>-Claisen-type C–C bond cleavage of diketones with tropylium catalyst
作者:M. A. Hussein、V. T. Huynh、R. Hommelsheim、R. M. Koenigs、T. V. Nguyen
DOI:10.1039/c8cc07329e
日期:——
cleavage in this reaction is usually promoted by a number of transition-metal Lewis acid catalysts or organic Brønsted acids/bases. Herein we report a new convenient and efficient method utilizing the tropylium ion as a mild and environmentally friendly organocatalyst to mediate retro-Claisen-type reactions. Using this method, a range of synthetically valuable substances can be accessed via solvolysis of
Regiodivergent Halogenation of Vinylogous Esters: One-Pot, Transition-Metal-Free Access to Differentiated Haloresorcinols
作者:Xiaohong Chen、Jenny S. Martinez、Justin T. Mohr
DOI:10.1021/ol503561x
日期:2015.1.16
vinylogous esters and sulfonyl halide halogen donors. Either the 4- or 6-haloresorcinol isomer is accessible from a common precursor. In contrast to conventional oxidants for arene halogenation, mild sulfonyl halides allow broad functional group compatibility. The strategy inherently differentiates the two resorcinol oxygen atoms and enhances the potential for complexmolecule synthesis.
Practical regioselective halogenation of vinylogous esters: synthesis of differentiated mono-haloresorcinols and polyhalogenated resorcinols
作者:Xiaohong Chen、Xiaoguang Liu、Jenny S. Martinez、Justin T. Mohr
DOI:10.1016/j.tet.2016.02.006
日期:2016.6
A practical and efficient method for the direct, regioselective conversion of vinylogousesters to haloresorcinols is reported. Control of the reaction conditions enables synthesis of either the 4- or 6-haloresorcinol isomers from a common precursor with excellent regiocontrol and high yield. The generality and functional group tolerance of this novel protocol is demonstrated. The utility of this methodology
Cyclic enaminone as new chemotype for selective cyclooxygenase-2 inhibitory, anti-inflammatory, and analgesic activities
作者:Raj Kumar、Nirjhar Saha、Priyank Purohit、Sanjeev K. Garg、Kapileswar Seth、Vachan S. Meena、Sachin Dubey、Khyati Dave、Rohit Goyal、Shyam S. Sharma、Uttam C. Banerjee、Asit K. Chakraborti
DOI:10.1016/j.ejmech.2019.111601
日期:2019.11
were assessed for in vivo anti-inflammatory activity in carrageenan induced rat paw edema assay. The anti-inflammatory activity of 7d was comparable to that of celecoxib at a dose of 12.5 mg/kg. However, the compounds 8 and 9 were more/equally effective as anti-inflammatoryagent compared to celecoxib at the doses of 12.5 mg/kg and 25 mg/kg and also exhibited anti-inflammatory activity comparable to that