Copper-Catalysed Asymmetric 1,4-Addition of Organozinc Compounds to Linear Aliphatic Enones Using 2,2′-Dihydroxy 3,3′-Dithioether Derivatives of 1,1′-Binaphthalene
Copper-Catalysed Asymmetric 1,4-Addition of Organozinc Compounds to Linear Aliphatic Enones Using 2,2′-Dihydroxy 3,3′-Dithioether Derivatives of 1,1′-Binaphthalene
β-Hydroxy ketones can be reduced to the corresponding 1,3-diols in high yields and with excellent diastereoselectivity by carrying out the reaction with BH3·pyridine in CH2Cl2 at −78 °C in the presence of TiCl4. This protocol is general and chemoselective: excellent results are obtained when the substituents are primary, secondary, tertiary alkyl chains or aromatic moieties. The presence of reducible
β-羟基酮可以通过在-78 °C 和 TiCl4 存在下与 BH3·吡啶在 CH2Cl2 中进行反应,以高产率和优异的非对映选择性还原为相应的 1,3-二醇。该方案是通用的且具有化学选择性:当取代基为伯、仲、叔烷基链或芳族部分时,可获得优异的结果。可以很好地容忍可还原的官能团如溴、硝基和氰基的存在。
Regiospecific directed aldol reactions of methyl ketones with aldehydes