A new strategy for constructing indolizino[1,2-b]quinolin-9(11H)-ones (ring cores of camptothecins) from readily available isocyanoarenes and N-(alkyl-2-yn-1-yl)pyridin-2(1H)-ones has been developed through a visible-light-induced radical cascade cyclization process. The reaction proceeds under mild conditions with fair to excellent yields. The easy introduction of substituents for both reactants and
从易得的异氰基芳烃和N-(烷基-2-yn-1-基)吡啶-2(n)合成吲哚并[1,2 - b ]喹啉9(11 H)-(喜树碱的环核)的新策略已经通过可见光诱导的自由基级联环化过程开发了1 H)-one。反应在温和的条件下进行,产率中等至优异。容易为两种反应物引入取代基以及反应对官能团的宽容度使其成为通向喜树碱及其衍生物核心的直接途径。
Glycosyl-Templated Chiral Helix Stapling of Ethynylpyridine Oligomers by Alkene Metathesis between Inter-Pitch Side Chains
作者:Hajime Abe、Fumihiro Kayamori、Masahiko Inouye
DOI:10.1002/chem.201501102
日期:2015.6.22
and D/L‐mannosyl‐linked ethynylpyridineoligomers have been developed with 4‐(3‐butenyloxy)pyridine units having alkenesidechains. The helical structures are successfully stapled by alkenemetathesis of the sidechains. Subsequent removal of the chiral templates by acidolysis produces template‐free stapledoligomers. The chiral, template‐free, stapledoligomers show chiral helicity, which is resistant
Selective N-functionalization of 6-substituted-2-pyridones
作者:Hui Liu、Sung-Bo Ko、Hubert Josien、Dennis P. Curran
DOI:10.1016/0040-4039(95)01917-7
日期:1995.12
6-Substituted-2-pyridones can be selectively N-alkylated by treatment with NaH/LiBr in a mixture of DMF and DME. Yields of N-propargylated, N-allylated, and other N-functionalized products are good, and only small amounts of the isomeric O-alkylated product (<10%) are typically formed.
Concentration- and Time-Dependent Eccentric Changes in Circular Dichroism of Saccharide-Linked Ethynylpyridine Oligomer with Copper(II) Ions
作者:Hajime Abe、Yuki Ohishi、Masahiko Inouye
DOI:10.1021/jo300735j
日期:2012.6.1
We studied the preparation and circular dichroism (CD) behavior of 2,6-pyridylene ethynylene octameric oligomer linked to a beta-D-glucoside moiety with a C20-alkylene chain. The addition of Cu(OTf)(2) salt led to a remarkable enhancement of the first CD band of the oligomer, and an unexpected concentration and time dependency were observed. For example, when 1.0 X 10(-3) M of Cu(OTf)(2) was added to a 1,2-dichloroethane solution of the oligomer (5.0 X 10(-4) M, unit concentration), the CD band appeared in the positive at first and gradually inverted into the negative with time.
Tandem radical reactions of isonitriles with 2-pyridonyl and other aryl radicals: Scope and limitations, and a first generation synthesis of (±)-camptothecin
作者:Dennis P. Curran、Hui Liu、Hubert Josien、Sung-Bo Ko
DOI:10.1016/0040-4020(96)00633-3
日期:1996.8
isonitriles provides tetra- and penta-cyclic products in a single step by a sequence of radical addition to the isonitrile followed by two cyclizations. The scope and limitations of the process are described along with a first generation synthesis of racemic camptothecin.