Cu-Catalyzed Stereoselective γ-Alkylation of Enones
作者:Xiaohong Chen、Xiaoguang Liu、Justin T. Mohr
DOI:10.1021/jacs.6b02565
日期:2016.5.25
This method constitutes a novel approach to the challenging 1,6-dioxygenation motif. A range of γ-substituted enones, including many bearing all-carbon quaternary centers, are available through a simple protocol under mild reaction conditions with superb functional group compatibility. Excellent stereoinduction is observed providing controlled access to challenging stereochemical arrays.
The oxidationproducts of a number of 4- and 5-monosubstituted and 4,6-disubstituted pyrogallols are discussed. 4-Alkylpyrogallols yield the corresponding 4′,7-dialkylpurpurogallins and the structures of the products resulting from the further oxidation of these compounds with alkaline hydrogen peroxide are elucidated. Oxidation of 5-mono and 4,6-dialkylpyrogallol derivatives yield characteristic white
Copper-catalyzed direct alkylation of heteroarenes
作者:Cédric Theunissen、Jianjun Wang、Gwilherm Evano
DOI:10.1039/c6sc05622a
日期:——
process is reported for the directalkylation of C–H bonds in heteroarenes, privileged scaffolds in many areas of science. This reaction is based on the copper-catalyzed addition of alkyl radicals generated from activated secondary and tertiary alkyl bromides to a wide range of arenes, including furans, thiophenes, pyrroles, and their benzo-fused derivatives, as well as coumarins and quinolinones.
Palladium-Catalyzed Alkynylation of Secondary α-Bromo Carbonyl Compounds via Stille Coupling
作者:Jun Yong Kang、Brian T. Connell
DOI:10.1021/jo200939u
日期:2011.8.19
A catalytic intermolecular cross-coupling reaction that couples secondary α-bromo carbonylcompounds with alkynylstannanes to form secondary alkynyl carbonylcompoundsvia palladium catalysis employing the XPhos ligand is described.
Zinc–silver/graphite mediated Reformatsky-reaction of furanoid aldonolactones with α-bromo-esters allows the synthesis of α-substituted 3-ulosonic acids in high yields.