(<i>R</i>)- and (<i>S</i>)-4-TIPS-3-butyn-2-ol. Useful Precursors of Chiral Allenylzinc and Indium Reagents
作者:James A. Marshall、Patrick Eidam、Hilary Schenck Eidam
DOI:10.1021/jo060542k
日期:2006.6.1
purity by reduction of the ynone precursor 4 with the Noyori N-tosyl-1,2-diphenylethylenediamineruthenium cymene catalyst is described. The mesylate derivative of the (S) enantiomer (1c) is converted in situ to an allenylzinc or indium reagent in the presence of a catalyst derived from Pd(OAc)2 and Ph3P and either Et2Zn or InI. A second in situ addition of these reagents to aldehydes leads to anti homopropargylic
描述了通过用Noyori N-甲苯磺酰基-1,2-二苯基乙烯二胺钌c烯催化剂还原炔酮前体4来获得> 95%对映体纯度的4-TIPS-3-丁炔-2-醇对映体的便利途径。(S)对映异构体(1c)的甲磺酸酯衍生物在衍生自Pd(OAc)2和Ph 3 P以及Et 2的催化剂存在下原位转化为烯丙基锌或铟试剂锌或铟 将这些试剂第二次原位添加到醛中会产生抗均丙醇加合物。加入通常以高(60-90%)的产率进行,具有适度至优异的非对映选择性和高对映选择性。用手性α-甲基和α-甲硅烷氧基醛仅观察到轻微的不匹配(<5%)。添加到α-取代的烯醛具有很高的非对映选择性,而β,β-二取代的烯醛可提供约。正反加合物的2:1混合物。