- NOVEL PROCESS FOR THE PREPARATION OF 2H-CHROMENES
-
The invention concerns a novel process for the preparation of 2H-chromenes of formula I and formula 5 and valuable intermediates of formulae 3 and 4 of this process.
- -
-
Page/Page column 6
(2010/02/10)
-
- Pt(IV)-catalyzed cyclization of arene-alkyne substrates via C-H bond functionalization
-
We herein report that PtCl4 has proven to be a hydroarylation catalyst with an efficiency and substrate scope superior to previously known methods. This catalyst demonstrated consistent performance with arene-yne substrates of diverse structural features, including propargyl ethers, propargylamines, and alkynoate esters, providing good to excellent yields of the 6-endo products (chromenes, dihydroquinolines, and coumarins). In contrast, Pt(II), Pd(II), and Ga(III) salts were shown to be sensitive to the substitution on the alkyne moiety. PtCl4 is compatible with both terminal and disubstituted alkynes, as well as with various functionalities on the arene ring, including methyl, methoxyl, hydroxyl, protected amine, and halide.
- Pastine, Stefan J.,Youn, So Won,Sames, Dalibor
-
p. 8859 - 8868
(2007/10/03)
-
- Diamino pyrimidines
-
Compounds of formula I STR1 wherein either R1 signifies straight-chain C5-10 -alkyl, branched C3-5 -alkyl, C3-6 -cycloalkyl or C3-5 ω-carboxyalkyl and R2 and R3 signify C1-5
- -
-
-