کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1328230 | 977549 | 2007 | 6 صفحه PDF | دانلود رایگان |
The Zr-catalyzed methylalumination of heterosubstituted arylethynes containing O, S, Cl, and Si can proceed in high yields (>70%) and in a highly regio- and stereoselective manner (⩾98–99%), although SO2Ph, Br, and Cl in a benzylic position present serious chemoselectivity-related problems. The low regioselectivity of 60% initially observed with o-ethynylphenol (1a) has been elevated to ⩾98% through the use of either a catalytic amount of Zr(ebi)Cl2 or Zr(2-Me-Ind)2Cl2 or, more conveniently, the stoichiometric amount of ZrCp2Cl2, ZrCp2MeCl, or ZrCp2Me2 in conjunction with the use of a deficient amount (0.9 molar equiv.) of I2 for subsequent iodinolysis.
The Zr-catalyzed methylalumination of heterosubstituted arylethynes containing O, S, Cl, and Si can proceed in high yields (>70%) and in a highly regio- and stereoselective manner (⩾98–99%), although SO2Ph, Br, and Cl in a benzylic position present serious chemoselectivity-related problems. The low regioselectivity of 60% initially observed with o-ethynylphenol (1a) has been elevated to ⩾98% through the use of either a catalytic amount of Zr(ebi)Cl2 or Zr(2-Me-Ind)2Cl2 or, more conveniently, the stoichiometric amount of ZrCp2Cl2, ZrCp2MeCl, or ZrCp2Me2 in conjunction with the use of a deficient amount (0.9 molar equiv.) of I2.Figure optionsDownload as PowerPoint slide
Journal: Journal of Organometallic Chemistry - Volume 692, Issue 21, 1 October 2007, Pages 4731–4736