A versatile synthesis of tricyclic analogues of quinolone antibacterial agents: Use of a novel reformatsky reaction
作者:Joseph P Michael、Charles B de Koning、Trevor V Stanbury
DOI:10.1016/s0040-4039(97)82976-0
日期:1996.12
A simple synthesis of tricyclic analogues of the quinolone antibiotics bearing a diverse range of substituents on the aromatic ring is described. The key steps involve unprecedented Reformatsky reaction between diethyl bromomalonate and N-arylpyrrolidine-2-thiones 8, followed by cyclisation of the resulting enaminone intermediates 9 in polyphosphoric acid.
Reformatsky reactions with N-arylpyrrolidine-2-thiones: synthesis of tricyclic analogues of quinolone antibacterial agents
作者:Joseph P Michael、Charles B de Koning、Gladys D Hosken、Trevor V Stanbury
DOI:10.1016/s0040-4020(01)00964-4
日期:2001.11
Abstract A convenientsynthesis of 5-oxo-1,2,3,5-tetrahydropyrrolo[1,2- a ]quinoline-4-carboxylic acids, tricyclic analogues of the quinolone antibiotics, is described. Key steps in the route are a novel zinc-mediated Reformatsky reaction between diethyl bromomalonate and N -arylpyrrolidine-2-thiones 18 , and cyclisation of the resulting diethyl pyrrolidinylidenemalonate intermediates 19 in polyphosphoric
secondary thioamides with diaryliodonium salts under basic, transition metal-free conditions resulted in chemoselective S-arylation to provide aryl thioimidates in good to excellent yields. Equimolar amounts of thioamide, base and diaryliodonium salt were sufficient to obtain a diverse selection of products within short reaction times. Reactions with thiolactams delivered N-arylated thioamides in good
Visible‐Light‐Mediated C(sp
<sup>3</sup>
)–H Thiocarbonylation for Thiolactam Preparation with Potassium Sulfide
作者:Wei Tan、Cuihong Wang、Xuefeng Jiang
DOI:10.1002/cjoc.201900360
日期:2019.12
thiolactam preparation with potassium sulfide via visible‐light‐mediated C(sp3)–H thiocarbonylation, in which polysulfide dianions and radical anions generated from potassium sulfide were the key active species. A variety of thiolactams were straightforward established under mild conditions. Moreover, it was successfully applied to structural modification of tetrahydroberberine.
An anti-selective direct catalytic asymmetric aldol reaction of thiolactam is described. A soft Lewis acid/hard Brønsted base cooperative catalyst comprised of mesitylcopper/(R,R)-Ph-BPE exhibited high catalytic performance to produce an anti-aldol product with high stereoselectivity. The highly chemoselective nature of the present catalysis allows for the use of enolizable aldehydes as aldol acceptors