The fischer indolisation reaction and the synthesis of dihydroindenoindoles
摘要:
The Fischer reaction between indanones and certain alkoxyarylhydrazines fails; the indanones are returned unreacted and the arylhydrazines are converted into the corresponding alkoxy-2-chloroarylamines and other products. A new N-amination route to arylhydrazines from the arylamines has been developed and it has been demonstrated that problems with the indolisation of alkoxyarylhydrazones can be circumvented by ring closures of their O-tosylated analogues. Some results using the Lepke synthesis of indoles are recorded.
Synthesis and structure–activity relationships of a series of substituted 2-(1H-furo[2,3-g]indazol-1-yl)ethylamine derivatives as 5-HT2C receptor agonists
A series of novel indazole derivatives were synthesized, and their structure-activity relationships examined in order to identify potent and selective 5-HT2C receptor agonists. Among these compounds, (S)-2-(7-ethyl-1H-furo[2,3-g]indazol-1-yl)-1-methylethylamine (YM348) had a good in vitro profile, that is, high agonistic activity to the human 5-HT2C receptor subtype (EC50 = 1.0 nM) and high selectivity
Mercuric Triflate Catalyzed Cycloisomerization of Alkynyl-1,3-Cyclohexanedione and Alkynyl-1,3-Cyclopentanedione
作者:Mugio Nishizawa、Hiroshi Imagawa、Shuhei Kotani
DOI:10.1055/s-2006-932464
日期:——
Mercuric triflate was used to catalyze cycloisomerization of alkynyl-1,3-cyclohexanediones and cyclopentanediones to give fused oxabicyclic systems under mild reaction conditions with high catalytic turnover up to 1000 times.
Direct Palladium-Catalyzed C-4 Arylation of Tri-substituted Furans with Aryl Chlorides: An Efficient Access to Heteroaromatics
作者:Hai Yang、Zhishuo Zheng、Jian Zeng、Huajie Liu、Bing Yi
DOI:10.5012/bkcs.2012.33.8.2623
日期:2012.8.20
A series of functionalized furans were synthesized by way of a palladium -catalyzed coupling reaction of 2,3,5trisubstituted furans with aryl chlorides through C-H bond cleavages at C-4position. The feature of the reaction was facilitative preparation of furan derivatives with good functional group tolerance. All reactions gave the desired products in moderate to good yields in the presences of BuAd2P
通过钯催化的2,3,5三取代呋喃与芳基氯通过C-4位CH键断裂的偶联反应合成了一系列功能化呋喃。该反应的特点是便于制备具有良好官能团耐受性的呋喃衍生物。在 BuAd2P 和 t-BuOK 的存在下,在 DMF 中 120 o C 15 小时后,所有反应均以中等至良好的收率得到所需产物。
Dipolar cycloaddition of rhodium carbenoids with vinyl esters. Total synthesis of pongamol and lanceolatin B
作者:Michael C. Pirrung、Yong Rok Lee
DOI:10.1016/s0040-4039(00)73399-5
日期:1994.8
A new method for dipolarcycloaddition of diazocyclohexane-1,3-diones, leading to benzofuran derivatives, has been applied to the totalsynthesis of natural products from Tephrosia and Pongamia.
Under the acidic conditions, substituted furans were constructed from γ-alkynyl ketones through corresponding allene intermediates in one-pot. The methodology was also tailored to a series of the Ugi reaction products for the synthesis of 6-methylpyrazin-2(1H)-one derivatives. The current method offered significant advantages for the combinatorial applications of these chemical scaffolds.