当前位置：
X-MOL 学术
›
J. Org. Chem.
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Evans Enolates: Structures and Mechanisms Underlying the Aldol Addition of Oxazolidinone-Derived Boron Enolates
The Journal of Organic Chemistry ( IF 3.3 ) Pub Date : 2017-07-07 00:00:00 , DOI: 10.1021/acs.joc.7b01365 Zirong Zhang 1 , David B. Collum 1
The Journal of Organic Chemistry ( IF 3.3 ) Pub Date : 2017-07-07 00:00:00 , DOI: 10.1021/acs.joc.7b01365 Zirong Zhang 1 , David B. Collum 1
Affiliation
|
The soft enolization of an acylated oxazolidinone using di-n-butylboron triflate (n-Bu2BOTf) and trialkylamines and subsequent aldol addition was probed structurally and mechanistically using a combination of IR and NMR spectroscopies. None of the species along the reaction coordinate show a penchant for aggregating. Complexation of the acylated oxazolidinone by n-Bu2BOTf was too rapid to monitor, as was the subsequent enolization with Et3N (triethylamine). The preformed n-Bu2BOTf·Et3N complex, displaying muted Lewis acidity and affiliated tractable rates, reveals a rate-limiting complexation via a transition structure with a complicated counterion. n-Bu2BOTf·i-Bu3N bearing a hindered amine shifts the rate-limiting step to proton transfer. Rate studies show that the aldol addition with isobutyraldehyde occurs as proffered by others.
中文翻译：
埃文斯烯醇盐：恶唑烷酮衍生的硼烯醇盐的醛醇缩合基础的结构和机理
使用二-酰化的恶唑烷酮的软烯醇化Ñ -butylboron三氟甲磺酸酯（Ñ -Bu 2 BOTf）和三烷基胺和随后的醛醇加成物探测结构上和机械上用IR和NMR光谱的组合。沿着反应坐标的所有物种均未显示出易于聚集的倾向。通过酰化的恶唑烷酮的络合Ñ -Bu 2 BOTf太快速监测，因为是用Et随后的烯醇化3 N（三乙胺）。预成形Ñ -Bu 2 BOTf·的Et 3N络合物显示出弱的路易斯酸度和相关的可处理速率，通过具有复杂抗衡离子的过渡结构揭示了限速络合物。Ñ -Bu 2 BOTf·我-Bu 3 Ñ轴承受阻胺移位的限速步骤，质子转移。速率研究表明，异丁醛与羟醛的加成反应与其他人一样。
更新日期：2017-07-07
中文翻译：
埃文斯烯醇盐：恶唑烷酮衍生的硼烯醇盐的醛醇缩合基础的结构和机理
使用二-酰化的恶唑烷酮的软烯醇化Ñ -butylboron三氟甲磺酸酯（Ñ -Bu 2 BOTf）和三烷基胺和随后的醛醇加成物探测结构上和机械上用IR和NMR光谱的组合。沿着反应坐标的所有物种均未显示出易于聚集的倾向。通过酰化的恶唑烷酮的络合Ñ -Bu 2 BOTf太快速监测，因为是用Et随后的烯醇化3 N（三乙胺）。预成形Ñ -Bu 2 BOTf·的Et 3N络合物显示出弱的路易斯酸度和相关的可处理速率，通过具有复杂抗衡离子的过渡结构揭示了限速络合物。Ñ -Bu 2 BOTf·我-Bu 3 Ñ轴承受阻胺移位的限速步骤，质子转移。速率研究表明，异丁醛与羟醛的加成反应与其他人一样。
京公网安备 11010802027423号