Environmentally-Friendly Wohl-ZieglerBromination: Ionic-Liquid Reaction and Solvent-Free Reaction
作者:Hideo Togo、Takeshi Hirai
DOI:10.1055/s-2003-38379
日期:——
Environmentally-friendly Wohl-Ziegler bromination of benzylic methyl groups was successfully carried out in ionic-liquid and solvent-free systems, to produce the corresponding benzylic bromides in good to moderate yields.
with cyanoaokenes substituted with ester groups catalyzed by a Sn and Mg ate complex. The diastereoselectivity was affected by the halogen of the catalyst and electron‐withdrawing groups on the cyanoalkene. The transformation of the spirohexane was carried out to afford a cyclopentanoid which has been prepared only by a transition metal catalyst.
Novel transformation of methylenecyclopropanes (MCPs) with acyl cyanoalkenes has been achieved to give oxaspiro[2.5]octenes. This annulation is successfully catalyzed by magnesium halides under mild reaction conditions, and shows a broad functional group tolerance. The reaction includes a rare reaction course, which involves an intramolecular oxa-Michael addition of Mg enolate after the ring opening
Preparation of the conjugated polyene chains with the 1,4-dimethyl substitution
作者:Hye-Sun Jeon、Sangho Koo
DOI:10.1016/j.tetlet.2004.07.146
日期:2004.9
Allylic sulfones undergo the conjugate addition to diethyl chloroisopropylidenemalonate, followed by intramolecular cyclopropanation. DBU-promoted ring opening and subsequent desulfonation reactions of the resulting adduct produce the conjugatedpolyenechains with the 1,4-dimethyl substitution.
2,2-bis-(hydroxymethyl)cyclopropylidenemethyl-purines and pyrmindines as antiviral agents
申请人:Zemlicka Jiri
公开号:US20050113393A1
公开(公告)日:2005-05-26
Compounds which are active against viruses have the following formulas:
wherein B is a purine or pyrimidine heterocyclic ring or base. In a preferred embodiment, the purine include 6-aminopurine (adenine), 6-hydroxypurine (hypoxanthine), 2-amino-6-hydroxypurine (guanine), 2,6-diamino-purine, 2-amino-6-azidopurine, 2-amino-6-halo substituted purines such as 2-amino-6-chloropurine, 2-amino-6-fluoropurine, 2-amino-6-alkoxypurines such as 2-amino-6-methoxypurine, 2-amino-6-cyclopropylaminopurine, 2-amino-6-alkylamino or 2-amino-6-dialkylamino substituted purines, 2-amino-6-thiopurine, 2-amino-6-alkylthio substituted purines, 3-deazapurines, 7-deazapurines and 8-azapurines. The pyrimidine incorporates cytosine, uracil and thymine, 5-halo substituted cytosines and uracils, 5-alkyl substituted cytosines and uracils including derivatives with a saturated or unsaturated alkyl group and 6-azapyrimidines.