三氯化铟是脂族胺,β-酮酸酯,α,β-不饱和醛和乙醇之间连续四组分反应的有效催化剂,可提供6-乙氧基-1,4,5,6-四氢吡啶,并转化为在中性Al 2 O 3存在下通过乙醇消除反应原位合成5,6-未取代的1,4-二氢吡啶,这是一种非常有效的一锅操作方案,由无环结构,易于获得的起始原料组成,涉及到生成两个CNσ和一个CCπ键。由此产生的二氢吡啶文库的结构多样性通过其C-2位的碱促进的γ-烷基化而扩展。通过将它们用作Yb(OTf)3催化的亚氨基Diels-Alder(Povarov)反应的亲双烯体,证明了将这些1,4-二氢吡啶用于分子多样性和复杂性的简便生成具有选择性,从而导致非对映选择性地导致六氢苯并[ h ] [1] ,6]-萘啶衍生物含有三个相邻的立体中心。吡啶并[2,1- a]衍生的稠合二氢吡啶的合成还使用四组分四氢吡啶合成/闭环复分解/消除策略获得了氮杂(高喹啉嗪)骨架。
A Very Efficient Cerium(IV) Ammonium Nitrate Catalyzed, Four-Component Synthesis of Tetrahydropyridines and Its Application in the Concise Generation of Functionalized Homoquinolizine Frameworks
作者:Vellaisamy Sridharan、Swarupananda Maiti、J. Carlos Menéndez
DOI:10.1002/chem.200900044
日期:2009.4.27
Molecular diversity: A cerium(IV) ammonium nitrate (CAN) catalyzed, four‐component reaction from very simple acyclic starting materials afforded densely substituted tetrahydropyridines, which were transformed into homoquinolizines by using a γ‐alkylation–ring‐closing metathesis (RCM) sequence (see scheme).
Synthesis of a Library of 5,6-Unsubstituted 1,4-Dihydropyridines Based on a One-Pot 4CR/Elimination Process and Their Application to the Generation of Structurally Diverse Fused Nitrogen Heterocycles
作者:Swarupananda Maiti、Vellaisamy Sridharan、J. Carlos Menéndez
DOI:10.1021/cc100084b
日期:2010.9.13
Diels−Alder (Povarov) reactions leading diastereoselectively to hexahydrobenzo[h][1,6]-naphthyridinederivatives containing three adjacent stereocenters. The synthesis of fused dihydropyridines derived from the pyrido[2,1-a]azepine (homoquinolizine) frameworks was also achieved using a four-component tetrahydropyridine synthesis/ring-closing metathesis/elimination strategy.
三氯化铟是脂族胺,β-酮酸酯,α,β-不饱和醛和乙醇之间连续四组分反应的有效催化剂,可提供6-乙氧基-1,4,5,6-四氢吡啶,并转化为在中性Al 2 O 3存在下通过乙醇消除反应原位合成5,6-未取代的1,4-二氢吡啶,这是一种非常有效的一锅操作方案,由无环结构,易于获得的起始原料组成,涉及到生成两个CNσ和一个CCπ键。由此产生的二氢吡啶文库的结构多样性通过其C-2位的碱促进的γ-烷基化而扩展。通过将它们用作Yb(OTf)3催化的亚氨基Diels-Alder(Povarov)反应的亲双烯体,证明了将这些1,4-二氢吡啶用于分子多样性和复杂性的简便生成具有选择性,从而导致非对映选择性地导致六氢苯并[ h ] [1] ,6]-萘啶衍生物含有三个相邻的立体中心。吡啶并[2,1- a]衍生的稠合二氢吡啶的合成还使用四组分四氢吡啶合成/闭环复分解/消除策略获得了氮杂(高喹啉嗪)骨架。