کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5223445 | 1383487 | 2010 | 13 صفحه PDF | دانلود رایگان |
The synthesis of chiral, nonracemic butadienylcarbinols by employing intermediate (trimethylsilyl)methylallenic alcohols is described. Allenic alcohols are obtained by treatment of aldehydes with (4-bromobut-2-ynyl)trimethylsilane in the presence of a catalytic amount of CrCl3 or CrCl2. Several new tridentate bis(oxazolinyl)carbazole ligands were synthesized and evaluated as the source of chirality. The synthesis of chiral allenic alcohols can be achieved in good yields (58–88%) and enantioselectivities (55–78% ee). Allenic alcohols may be treated with TBAF or 2 M HCl to provide the desired dienes in 43–86% yields. Alternatively, the (trimethylsilyl)methyl allenic alcohols afford iodobutadienyl carbinols when treated with N-iodosuccinimide.
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Journal: Tetrahedron - Volume 66, Issue 39, 25 September 2010, Pages 7707–7719