Either [1,3]- or [3,3]-sigmatropic rearrangements were selectively accessed by controlling the reaction temperature in the gold(III)-catalyzed tandem rearrangement/cyclization of (E)-2-(aryloxymethyl)alk-2-enoates to afford diversely substituted 3,4-dihydrocoumarin derivatives in moderate to good yields and in excellent regioselectivity.
INK COMPOSITION, INKJET RECORDING METHOD, PRINTED MATERIAL, PRODUCTION METHOD OF A PLANOGRAPHIC PRINTNG PLATE AND PLANOGRAPHIC PRINTING PLATE
申请人:YOKOI Kazuhiro
公开号:US20080257188A1
公开(公告)日:2008-10-23
The invention provides an ink composition comprising: a condensed cyclic lactone compound; a compound that generates an acid when irradiated with a radiation ray; a cationically polymerizable compound; and a colorant. Further, the invention provides an inkjet recording method using this ink composition, a printed material obtained by using the ink composition, and a planographic printing plate, and a method of producing a planographic printing plate.
Regiospecific Synthesis of 3,4-Dihydrocoumarins via Substrate-Controlled [1,3]- or [3,3]-Sigmatropic Rearrangement
A regiospecificsynthesis of 3,4-dihydrocoumarin derivatives has been achieved involving tandem rearrangement-cyclization of (E)-2-(aryloxymethyl)alk-2-enoates catalyzed by a Pd/Cu bimetallic system. Unexpected substrate-controlled [1,3]- or [3,3]-sigmatropic rearrangement was observed in the transformations. [1,3]-sigmatropic rearrangement - [3,3]-sigmatropic rearrangement - palladium/copper bimetallic
The synthesis of novel vicinal coumarin- and oxindole-functionalized dispiropyrrolidines and dispiropyrrolizidines containing three and four contiguous stereogenic centers, respectively, has been accomplished in excellent yields and with high regio- and stereoselectivity. The dispiro compounds are obtained via [3+2]-cycloaddition reactions between (E)-3-benzylidenechroman-2-one and the adduct generated