method for the α-trifluoromethoxylation of ketones is reported. Enol carbonates react with N-trifluoromethoxy-4-cyano-pyridinium, using the photoredox catalyst 4-CzIPN under 456 nm irradiation, affording the α-trifluoromethoxy ketones in ≤50% isolated yield and complete chemoselectivity. As shown by 29 examples, the reaction is general and proceeds very rapidly under batch (1 h) and flow conditions (2 min)
作者:M. Neeman、Marjorie C. Caserio、John D. Roberts、Williams S. Johnson
DOI:10.1016/0040-4020(59)80034-x
日期:1959.1
and of the epimeric cholestanols, 3β (e) > 3 α(a). The highly hindered alcoholic hydroxyl groups of isoborneol was not methylated by the newreagent. The methylation of weakly acidic phenols was catalyzed by FBA. The new methylation reaction was used to prepare directly methyl ethers of desoxycorticosterone and of testosterone, and to convert ascorbic acid selectively to its 2:3:6-trimethyl ether.
在催化量的氟硼酸(FBA)的存在下,重氮甲烷将醇羟基甲基化。脂肪族伯醇和无阻碍的仲醇的甲醚产率为84-98%,而叔和中等受阻仲醇的产率较低。在竞争实验中确定,异构丁醇的甲基化反应顺序为n > s > t,而异构体胆甾醇的3β(e)> 3α(a)。iso的高度受阻醇羟基冰片没有被新试剂甲基化。FBA催化弱酸性酚的甲基化。该新的甲基化反应用于直接制备脱氧皮质酮和睾丸酮的甲基醚,并将抗坏血酸选择性地转化为其2:3:6-三甲基醚。
1,3,6-DIOXAZOCAN-2-ONES AND ANTIMICROBIAL CATIONIC POLYCARBONATES THEREFROM
申请人:Agency for Science, Technology and Research
公开号:US20150264932A1
公开(公告)日:2015-09-24
Eight-membered ring cyclic carbonates comprising a ring nitrogen at position 6 (1,3,6-dioxazocan-2-ones) were prepared by reaction of precursor diols with active carbonates. The ring nitrogen is linked to a pendant group Y′ via a methylene linking group. The cyclic carbonates undergo organocatalyzed ring opening polymerization to form an initial polycarbonate comprising a backbone tertiary amine group. Quaternization of the initial polycarbonates forms cationic polycarbonates comprising a positive-charged backbone quaternary nitrogen. The cationic polycarbonates can be potent antimicrobial agents.
VITAMIN FUNCTIONALIZED GEL-FORMING BLOCK COPOLYMERS FOR BIOMEDICAL APPLICATIONS
申请人:INTERNATIONAL BUSINESS MACHINES CORPORATION
公开号:US20180117162A1
公开(公告)日:2018-05-03
Gel-forming block copolymers were prepared comprising i) a central hydrophilic block consisting essentially of a divalent poly(ethylene oxide) chain and ii) two peripheral monocarbonate or polycarbonate hydrophobic blocks linked to the central block by linking groups bearing one or more hydrogen bond forming *—N(H)—* groups. The hydrophobic blocks comprise one or more vitamin-bearing subunits. The gel-forming block copolymers can be used to prepare various biodegradable and/or biocompatible hydrogel and organogel drug compositions, in particular antimicrobial and/or anti-tumor drug compositions. The hydrogel compositions have utility in depot injections for drug delivery. The hydrogen bonding *—N(H)—* group(s) provide longer in vivo lifetime of the hydrogel before degradation and a more prolonged and controlled release rate of a hydrophobic drug compared to similar hydrogels prepared from poly(ethylene glycol).
NEUROACTIVE 19-ALKOXY-17-SUBSTITUTED STEROIDS, PRODRUGS THEREOF, AND METHODS OF TREATMENT USING SAME
申请人:Sage Therapeutics, Inc.
公开号:US20140235600A1
公开(公告)日:2014-08-21
The present disclosure is generally directed to neuroactive 19-alkoxy-17-substituted steroids as referenced herein, and pharmaceutically acceptable salts thereof, for use as, for example, an anesthetic, and/or in the treatment of disorders relating to GABA function and activity. The present disclosure is further directed to pharmaceutical compositions comprising such compounds.