The direct and controlled activation of a C(sp3)Hbond adjacent to an O atom is of particular synthetic value for the conventional derivatization of ethers or alcohols. In general, stoichiometricamounts of an oxidant are required to remove an electron and a hydrogen atom of the ether for subsequent transformations. Herein, we demonstrate that the activation of a CHbond next to an O atom could be
Highly regioselective and metal-free γ-addition of β-keto esters to isatins, catalyzed by DABCO: direct access to novel class of diversely functionalized 3-hydroxy-2-oxindole scaffolds
DABCO catalyzed, highly regioselective γ-addition of β-keto esters has been achieved in the aldol reaction with isatins to afford γ-(3-hydroxy-2-oxindole)-β-keto ester structural framework under metal-free condition. The generality of the method has been demonstrated by screening series of isatin electrophiles as well as linear and cyclic β-keto esters. Compare to the dianion method, the present method
The oxyfunctionalization of 4-methylcoumarins using dimethyldioxirane
作者:Sanja Ćavar、Franci Kovač
DOI:10.1002/kin.20412
日期:2009.6
efficient regioselective oxidation of the CC double bond of 4‐methylcoumarins with isolated dimethyldioxirane was investigated using UV–vis spectroscopy methods. In the excess of dimethyldioxirane, the pyrone ring of a coumarin skeleton is selectively epoxidated and hydroxylated in neutral media, in high yields. Kinetic analyses demonstrate two independent reaction pathways, epoxidation and hydroxylation
Synthesis of Deuterium-Labeled Derivatives of Dimethylallyl Diphosphate
作者:Hirekodathakallu V. Thulasiram、Richard M. Phan、Susan B. Rivera、C. Dale Poulter
DOI:10.1021/jo052384n
日期:2006.2.1
Short practical syntheses for five deuterium-labeled derivatives of dimethylallyl diphosphate (DMAPP) useful for enzymological studies are reported. These include the preparation of the Cl-labeled derivatives (R)-[1-H-2]3-methylbut-2-enyl diphosphate ((R)-[1-H-2]1-OPP) and (S)-[1-H-2]3-methylbut-2-enyl diphosphate ((S)-[1-H-2]1-OPP), the C2-labeled derivative [2-H-2]3-methylbut-2-enyl diphosphate ([2-H-2]1-OPP), and the methyl-labeled derivatives (E)-[4,4,4-H-2(3)]3-methylbut-2-enyl diphosphate ((E)-[4,4,4-H-2(3)]1-OPP) and (Z)-[4,4,4-H-2(3)]3-methyl-but-2-enyl diphosphate ((Z)[4,4,4-H-2(3)]1-OPP).
Rao; Towill; Jackson, Journal of the Indian Chemical Society, 1989, vol. 66, # 8-10, p. 654 - 655