N-Substituted phenoxazines and related aza analogs have been prepared from N-acetylated aryloxy anilides by transition-metal-free, base-catalyzed cyclization reactions. In the presence of a mixture of 10 mol % of N,N-dimethylethylenediamine (DMEDA) and 2 equiv of K2CO3 in toluene at 135 degrees C the products are obtained in high yields.
Intramolecular Carbonylation Reactions with Recyclable Palladium-Complexed Dendrimers on Silica: Synthesis of Oxygen, Nitrogen, or Sulfur-Containing Medium Ring Fused Heterocycles
作者:Shui-Ming Lu、Howard Alper
DOI:10.1021/ja053650h
日期:2005.10.1
Palladium-complexeddendrimers supported on silica were evaluated as catalysts for intramolecular carbonylation reactions. The results showed that dendritic catalysts display high activity, affording oxygen, nitrogen, or sulfur-containing seven- or eight-membered ring fused heterocycles in excellent yields. Moreover, these catalysts have competitive advantages in that they can be easily recovered by
Sequence of Intramolecular Carbonylation and Asymmetric Hydrogenation Reactions: Highly Regio- and Enantioselective Synthesis of Medium Ring Tricyclic Lactams
作者:Shui-Ming Lu、Howard Alper
DOI:10.1021/ja7111417
日期:2008.5.1
The intramolecular cyclocarbonylation reaction with palladium-complexed dendrimers on silica is a very effective method for the regioselective synthesis of methylene 8-, 9-, and 10-membered rings. The heterogeneous dendritic catalysts are easily recovered by simple filtration and reused for up to 10 cycles with only a slight loss of activity. Asymmetric hydrogenation of the resulting unsaturated heterocycles
The present invention provides novel heteroaryl compounds and analogues thereof, which are selective inhibitors of the human P2Y
1
receptor. The invention also provides for various pharmaceutical compositions of the same and methods for treating diseases responsive to modulation of P2Y
1
receptor activity.
Diazaphenoxazines and Diazaphenothiazines: Synthesis of the “Correct” Isomers Reveals They Are Highly Reactive Radical-Trapping Antioxidants
作者:Evan A. Haidasz、Derek A. Pratt
DOI:10.1021/acs.orglett.7b00615
日期:2017.4.7
The preparation of 2,4-diazaphenothiazines and 2,4-diazaphenoxazines via a copper-catalyzed intramolecular amination is described. Literature approaches-mhich utilize easily accessed (2'-aminophenyl) 4-pyri(mi)dyl sulfides undergo a Smiles rearrangement that gives rise to the 1,3-dinza derivatives instead, confirmed by X-ray crystallography. Inversion of the polarity of the cyclization avoids the rearrangement and affords the desired,products. Preliminary kinetic studies suggest :that 2,4-diazaphenothiazines and diazaphenoxazines, but not the 1,3-diaza isomers, are remarkably potent radical-trapping antioxidants.