receptor antagonist activity. In search of new chemical leads for the development of more potent NPY antagonists, a series of N,N‐disubstituted ω‐guanidino and ω‐aminoalkanoic acid amides were synthesized on the basis of structure‐activity relationships and molecular modeling studies of arpromidine and related imidazolylpropylguanidines. In one group of compounds the imidazole ring was retained whereas
Synthesis of Medium- and Large-Ring Compounds Initiated by Photochemical Decarboxylation of ω-Phthalimidoalkanoates
作者:Axel G. Griesbeck、Andreas Henz、Wolfgang Kramer、Johann Lex、Frank Nerowski、Michael Oelgemöller、Karl Peters、Eva-Maria Peters
DOI:10.1002/hlca.19970800324
日期:1997.5.12
reaction initiated by intramolecular photo electron transfer is described. Ring sizes available by this method span from 4 (benzazepine-1,5-dione 7) to 26 (cyclodipeptide 26e). Ground-state template formation is proposed as the explanation for the high efficiency of this reaction and for the decrease in reactivity in the presence of organic bases instead of metal carbonates. The crucial step in this
Silver-Catalyzed Decarboxylative Radical Azidation of Aliphatic Carboxylic Acids in Aqueous Solution
作者:Chao Liu、Xiaoqing Wang、Zhaodong Li、Lei Cui、Chaozhong Li
DOI:10.1021/jacs.5b06821
日期:2015.8.12
We report herein an efficient and general method for the decarboxylative azidation of aliphaticcarboxylicacids. Thus, with AgNO3 as the catalyst and K2S2O8 as the oxidant, the reactions of various aliphaticcarboxylicacids with tosyl azide or pyridine-3-sulfonyl azide in aqueous CH3CN solution afforded the corresponding alkyl azides under mild conditions. A broad substrate scope and wide functional
Silver-Catalyzed Decarboxylative Trifluoromethylation of Aliphatic Carboxylic Acids
作者:Xinqiang Tan、Zhonglin Liu、Haigen Shen、Pei Zhang、Zhenzhen Zhang、Chaozhong Li
DOI:10.1021/jacs.7b07944
日期:2017.9.13
The silver-catalyzed decarboxylativetrifluoromethylation of aliphatic carboxylicacids is described. With AgNO3 as the catalyst and K2S2O8 as the oxidant, the reactions of aliphatic carboxylicacids with (bpy)Cu(CF3)3 (bpy = 2,2'-bipyridine) and ZnMe2 in aqueous acetonitrile at 40 °C afford the corresponding decarboxylativetrifluoromethylation products in good yield. The protocol is applicable to
measured by T-T absorption, is much lower for 1 and 2 than for 3 or N-methyltrimellitimide (5') at ambient temperatures. The quantum yield (phi(delta)) of singlet molecular oxygen O2(1deltag) formation is substantial for 3 and 5' in several air- or oxygen-saturated solvents at room temperature, but small for 2 and 1. The quantum yield of decomposition is substantial (0.2-0.5) for 3 and small (<0.05)