Synthesis of Pyrrolidine C-Nucleosides via Heck Reaction
摘要:
[GRAPHICS]A novel method for the synthesis of pyrrolidine C-nucleosides has keen developed, The key step of the synthesis is the palladium(0)-mediated coupling of a disubstituted N-protected 2-pyrroline and 5-iodouracil. C-Nucleoside 14 and its N-methyl derivative 15 can easily be convened to the corresponding phosphoramidite building blocks for DNA synthesis.
Synthesis of 5-fluorovinyl derivatives of pyrimidines via Suzuki–Miyaura coupling and their 1,3-dipolar cycloaddition reactions with nitrones
作者:Hanna Wójtowicz-Rajchel、Henryk Koroniak
DOI:10.1016/j.jfluchem.2011.11.005
日期:2012.3
A simple two-step synthesis of a new class of fluorinated isoxazolidinyl derivatives of pyrimidine is described. The reactions proceed via the Suzuki–Miyaura coupling followed by highly regioselective 1,3-dipolarcycloaddition with nitrones. Removal of the pyrimidine protecting groups leads to a fluorinated isoxazolidine analogue of pseudouridine.
The present invention relates to inhibitors of aspartic proteinases, particularly, BACE. The present invention also relates to compositions thereof and methods therewith for inhibiting BACE activity in a mammal, and for treating Alzheimer's Disease and other BACE-mediated diseases.
(in six steps) or optically pure (in ten steps) from inexpensive norbornadiene. The methodology allows flexible manipulation of individual positions around the cyclopentane ring, namely highly diastereoselective installation of carbo- and heterocyclic substituents at position 1′, orthogonal functionalization of position 5′, and efficient inversion of stereochemistry at position 2′. Newly prepared carbocyclic
“Molecular Chameleons”. Design and Synthesis of a Second Series of Flexible Nucleosides
作者:Katherine L. Seley、Samer Salim、Liang Zhang、Peter I. O'Daniel
DOI:10.1021/jo048218h
日期:2005.3.1
The second series of flexible shape-modified nucleosides is introduced. The “fleximers” feature the purine ring systems split into their individual imidazole and pyrimidine components. This structural modification serves to introduce flexibility to the nucleoside while still retaining the elements essential for recognition. As a consequence, these structurally innovative nucleosides can more readily