Furan‐Based
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Quinodimethanes by Gold‐Catalyzed Dehydrogenative Heterocyclization of 2‐(1‐Alkynyl)‐2‐alken‐1‐ones: A Modular Entry to 2,3‐Furan‐Fused Carbocycles
strategy for in situ generation of furan‐based ortho‐quinodimethanes (o‐QDMs) by the gold(I)‐mediated dehydrogenative heterocyclization of 2‐(1‐alkynyl)‐2‐alken‐1‐ones in the presence of pyridine N‐oxide under mild reaction conditions was developed. These in situ furan‐based o‐QDMs were trapped by electron‐deficient olefins and alkynes, thus furnishing various 2,3‐furan‐fused carbocycles in good yields
Furans versus 4H-pyrans: catalyst-controlled regiodivergent tandem Michael addition–cyclization reaction of 2-(1-alkynyl)-2-alken-1-ones with 1,3-dicarbonyl compounds
作者:Yuanjing Xiao、Junliang Zhang
DOI:10.1039/b905267d
日期:——
The DBU-catalyzed reaction of 1-(1-alkynyl)-2-alken-1-ones with 1,3-dicarbonyl compounds produces 4H-pyrans in moderate to excellent yield, whereas the cationic Pd(II)-catalyzed reaction affords furans regioselectively.
Unexpected C–C bond cleavage of epoxide motif: Rhodium(<scp>i</scp>)-catalyzed tandem heterocyclization/[4+1] cycloaddition of 1-(1-alkynyl)oxiranyl ketones
作者:Tao Wang、Cui-Hong Wang、Junliang Zhang
DOI:10.1039/c0cc05650b
日期:——
A rhodium(I)-catalyzed tandem heterocyclization and formal [4+1] cycloaddition of 1-(1-alkynyl)oxiranyl ketones was developed, which provides a general, efficient and practical route to highly substituted furo[3,4-b]furan-3(2H)-ones, wherein the epoxide motif undergo unexpected C-C bond cleavage rather than the classical C-O bond cleavage.
DBU-catalyzed tandem additions of electron-deficient 1,3-conjugated enynes with 2-aminomalonates: a facile access to highly substituted 2-pyrrolines
作者:Xiuzhao Yu、Guanghua Zhou、Junliang Zhang
DOI:10.1039/c2cc30840a
日期:——
An efficient, metal free approach to highly substituted 2-pyrrolines by DBU-catalyzed tandem additions (a formal [3+2] cycloaddition) of electron-deficient 1,3-conjugated enynes and 2-aminomalonates under mild conditions was developed.
Diastereoselective Synthesis of Cyclopenta[
<i>c</i>
]furans by a Catalytic Multicomponent Reaction
作者:Stalin R. Pathipati、Angela van der Werf、Lars Eriksson、Nicklas Selander
DOI:10.1002/anie.201606108
日期:2016.9.19
A diastereoselective three‐component reaction between alkynyl enones, aldehydes and secondary amines is reported. With the aid of a benign indium catalyst, a range of highly substituted cyclopenta[c]furan derivatives can be obtained in a single‐step procedure. The formation of the stereodefined heterocyclic motifs takes place via in situ generation of enamines followed by two sequential cyclization
报道了炔基烯酮、醛和仲胺之间的非对映选择性三组分反应。借助良性铟催化剂,可以通过一步程序获得一系列高度取代的环戊[ c ]呋喃衍生物。立体定义的杂环基序的形成是通过原位生成烯胺,然后进行两个连续的环化步骤来进行的。