Copper-Catalyzed Allylations of Zirconocene Intermediates Generated from o-Alkenyl or o-Alkynylbenzyl Ether Derivatives and Zirconocene−Butene Complex
摘要:
o-Alkenyl or alkynyl benzylzirconocene intermediate, which was readily generated by the reaction of 2-alkoxymethyl-styrene or 2-alkoxymethyl-1-(trimethylsilylethynyl)-benzene derivative with zirconocene-butene complex (Negishi reagent, "Cp2Zr"), reacted with allyl or propargyl halides in the presence of a catalytic amount of CuCl to give allylation or allenylation products. Conversion to Dane's diene, which is a key intermediate for estrone synthesis, was efficiently carried out by enyne olefin metathesis of the allylation products.
Copper-Catalyzed Allylations of Zirconocene Intermediates Generated from <i>o</i>-Alkenyl or <i>o</i>-Alkynylbenzyl Ether Derivatives and Zirconocene−Butene Complex
作者:Yutaka Ikeuchi、Takeo Taguchi、Yuji Hanzawa
DOI:10.1021/jo048860b
日期:2005.1.1
o-Alkenyl or alkynyl benzylzirconocene intermediate, which was readily generated by the reaction of 2-alkoxymethyl-styrene or 2-alkoxymethyl-1-(trimethylsilylethynyl)-benzene derivative with zirconocene-butene complex (Negishi reagent, "Cp2Zr"), reacted with allyl or propargyl halides in the presence of a catalytic amount of CuCl to give allylation or allenylation products. Conversion to Dane's diene, which is a key intermediate for estrone synthesis, was efficiently carried out by enyne olefin metathesis of the allylation products.
Divergent Access to Seven/Five-Membered Rings Based on [1,6]-Hydride Shift/Cyclization Process
作者:Daiki Hoshino、Keiji Mori
DOI:10.1021/acs.orglett.1c03523
日期:2021.12.17
We have achieved a divergent access to seven/five-memberedrings based on a [1,6]-hydride shift/cyclization process from benzylidenemalonate with an o-alkoxymethyl group. Whereas Yb(OTf)3 afforded benzoxepines (with a seven-membered ring) selectively, indanes (with a five-memberedring) were the main products when Sc(OTf)3 was employed.