A highly regio- and stereoselective synthesis of (Z )-3-arylidene-2,3-dihydro-5H-1,4-benzodioxepin-5-ones and (Z )-3-arylidene-1,2,3,5-tetrahydro-4,1-benzoxazepin-5-ones through palladium–copper catalysis
作者:Gopeswar Chaudhuri、Nitya G. Kundu
DOI:10.1039/a908682j
日期:——
Sodium 2-(prop-2â²-ynyloxy)benzoate 1a reacted with the aryl iodides 2â10 in the presence of bis(triphenylphosphine)palladium(II) chloride, cuprous iodide and triethylamine in CH3CNâDMF to yield the disubstituted alkynes 11â19 in good yields (48â58%). Similarly, sodium 2-[N-benzyl-N-(prop-2â²-ynyl)]aminobenzoate 1b on reaction with aryl iodides under palladiumâcopper catalysis afforded the disubstituted alkynes 20â22. Compounds 11â19 on cyclisation with cuprous iodide in the presence of triethylamine in acetonitrile yielded the 3-arylidene-2,3-dihydro-5H-1,4-benzodioxepin-5-ones 23â31 in 61â83% yields. Similarly, compounds 20â22 on cyclisation gave 3-arylidene-1,2,3,5-tetrahydro-4,1-benzoxazepin-5-ones 32â34.
氢氧化钠2-(丙-2'-炔基氧基)苯甲酸钠1a在双(三苯基膦)氯化钯、碘化亚铜和三乙胺存在下,与芳基碘化物2–10反应,获得良好产率的二取代炔烃11–19(48–58%)。同样,氢氧化钠2-[N-苄基-N-(丙-2'-炔基)]氨基苯甲酸钠1b在钯-铜催化下与芳基碘化物反应,得到二取代炔烃20–22。化合物11–19在氯化亚铜和三乙胺的存在下于乙腈中环化,产生了3-芳基亚甲基-2,3-二氢-5H-1,4-苯并二氧庚烯-5-酮23–31,产率为61–83%。同样,化合物20–22环化后得到3-芳基亚甲基-1,2,3,5-四氢-4,1-苯并噁唑啉-5-酮32–34。