Long-acting contraceptive agents: Norethisterone esters of monoalkenyl and monoalkynyl acids
摘要:
The synthesis of nine new esters of norethisterone (17 alpha-ethynyl-17 beta-hydroxyestr-4-en-3-one) is described, with the esterifying acids bearing an acetylenic or olefinic function in a chain of eight or nine carbon atoms, for evaluation as long-acting contraceptive agents.
Use of Imidazo[1,5‐
<i>a</i>
]pyridin‐3‐ylidene as a Platform for Metal‐Imidazole Cooperative Catalysis: Silver‐Catalyzed Cyclization of Alkyne‐Tethered Carboxylic Acids
Silver complexes with 5‐(4‐(tert‐butyl)‐1H‐imidazol‐1‐yl)‐imidazo[1,5‐a]pyridin‐3‐ylidene ligands were synthesized as metal‐imidazole acid‐base cooperative catalysts. Single crystal XRD analysis revealed that the silver atom was located in the vicinity of the imidazole ring and that cationic silver complexes formed dimers through coordination between the silver metal and the imidazole pendant. These
Cyclization of alkynoic acids with gold catalysts: a surprising dichotomy between AuI and AuIII
作者:Hassina Harkat、Albert Yénimégué Dembelé、Jean-Marc Weibel、Aurélien Blanc、Patrick Pale
DOI:10.1016/j.tet.2008.10.112
日期:2009.2
ω-Acetylenic acids, substituted or not at their acetylenic end, could be efficiently cyclized to γ- or δ-alkylidene lactones in the presence of AuCl and K2CO3. In contrast AuCl3 led to lactone dimers, probably through cyclization and reductive dimerization. These AuI and AuIII catalyzed cyclizations were totally regioselective and most often highly stereoselective.
在AuCl和K 2 CO 3的存在下,可以在其乙炔基末端取代或不取代的ω-乙炔酸有效地环化为γ-或δ-亚烷基内酯。相反,AuCl 3可能通过环化和还原性二聚而导致内酯二聚体。这些Au I和Au III催化的环化反应完全是区域选择性的,并且通常是高度立体选择性的。
A simple, general distereoselective synthesis of 5-hydroxyalkylbutan-4-olides
作者:Charles W. Jefford、Ying Wang
DOI:10.1039/c39870001513
日期:——
cis- and trans-Hex-4-enoic acids and their 6-n-propyl and n-butyl derivatives, when treated with a 1.1 molar excess of m-chloroperbenzoic acid and Amberlyst-15 as catalyst in CH2Cl2 at 20 °C, gave the corresponding threo- and erythro-5-hydroxyalkylbutan-4-olides in quantitative yields.
Silver assisted heterocyclization of acetylenic compounds
作者:Patrick Pale、Josselin Chuche
DOI:10.1016/s0040-4039(00)96884-9
日期:1987.1
Silver assisted heterocyclization of acetylenic alcohols or acids provides an easy and mild access to α-methylene oxygenated heterocycles.
乙炔醇或酸的银辅助杂环化提供了轻松温和的α-亚甲基氧化杂环通道。
BIODEGRADABLE LIPIDS FOR THE DELIVERY OF ACTIVE AGENTS
申请人:ALNYLAM PHARMACEUTICALS, INC.
公开号:US20130195920A1
公开(公告)日:2013-08-01
The present invention relates to a cationic lipid having one or more biodegradable groups located in a lipidic moiety (e.g., a hydrophobic chain) of the cationic lipid. These cationic lipids may be incorporated into a lipid particle for delivering an active agent, such as a nucleic acid. The invention also relates to lipid particles comprising a neutral lipid, a lipid capable of reducing aggregation, a cationic lipid of the present invention, and optionally, a sterol. The lipid particle may further include a therapeutic agent such as a nucleic acid.