Regio- and Stereoselective Reductive Coupling of Bicyclic Alkenes with Propiolates Catalyzed by Nickel Complexes: A Novel Route to Functionalized 1,2-Dihydroarenes and -Lactones
作者:Dinesh Kumar Rayabarapu、Chien-Hong Cheng
DOI:10.1002/chem.200204506
日期:2003.7.7
5 a and b in 81 and 84% yield, respectively. In contrast to the results of 4 with 2, the reaction of dimethyl 7-oxabicyclo[2.2.1]-hept-5-ene-2,3-dicarboxylate (6) with propiolates 2a-d afforded the corresponding reductive coupling/cyclization products, bicyclo[3.2.1]γ-lactones 7a-d in good yields. The reaction provides a convenient one-pot synthesis of γ-lactones with remarkably high regio- and stereoselectivity
7-氧代苯并降冰片二烯衍生物la-d与丙炔酸烷基酯CH 3 C≡CCO 2 CH 3 (2a)、PhC≡CCO 2 Et (2b)、CH 3 (CH 2 ) 3 C≡CCO 2 CH 3 (2)进行还原偶联c)、CH 3 (CH 2 ) 4 C≡CCO 2 CH 3 (2d)、TMSC≡CCO 2 Et (2e)、(CH 3 ) 3 C≡CCO 2 CH 3 (2 f)和HC≡CCO 2 Et (2g) 在 [NiBr 2 (dppe)] (dppe = Ph 2 PCH 2 CH 2 PPh 2 )、H 2 O 和锌粉在乙腈中的存在下,在室温下得到相应的 2-alkenyl-1,2- dihydronapthalen-1-ol 衍生物 3 a - n 具有显着的区域选择性和非对映选择性,产率良好。类似地,7-氮杂苯并降冰片二烯衍生物1e与丙炔酸盐2a、b和d的反应顺利进行,以良好的收率和