Hydrogen Bonding-Assisted Enhancement of the Reaction Rate and Selectivity in the Kinetic Resolution of d,l-1,2-Diols with Chiral Nucleophilic Catalysts
Hydrogen Bonding-Assisted Enhancement of the Reaction Rate and Selectivity in the Kinetic Resolution of d,l-1,2-Diols with Chiral Nucleophilic Catalysts
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DOI：
10.1002/adsc.201700057
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发表时间：
2017-08-17
影响因子：
5.4
通讯作者：
Suga，Seiji
中科院分区：
文献类型：
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作者：
Fujii，Kazuki;Mitsudo，Koichi;Suga，Seiji
在仅0.5mol%的联萘基手性N，N-4-二甲氨基吡啶存在下，d，l-1，2-二醇的酰化动力学拆分非常有效（选择因子高达180）。 几个关键实验表明，催化剂的叔醇单元和底物的1，2-二醇单元之间的氢键对于加速单酰化速率和实现高对映选择性至关重要。该催化体系可应用于广泛的底物，包括具有高选择性因子的外消旋非环状和环状1，2-二醇。d，l-氢化苯偶姻和反式-1，2-环己二醇在多克规模（10 g）上的动力学拆分也以高选择性和在中等反应条件下进行：（i）非常低的催化剂负载（0.1 mol%）;（ii）容易实现的低反应温度（0 ℃）;（iii）高底物浓度（1.0 M）;和（iv）短反应时间（30 min）。
An extremely efficient acylative kinetic resolution ofd,l‐1,2‐diols in the presence of only 0.5 mol% of binaphthyl‐based chiralN,N‐4‐dimethylaminopyridine was developed (selectivity factor of up to 180). Several key experiments revealed that hydrogen bonding between thetert‐alcohol unit(s) of the catalyst and the 1,2‐diol unit of the substrate is critical for accelerating the rate of monoacylation and achieving high enantioselectivity. This catalytic system can be applied to a wide range of substrates involving racemic acyclic and cyclic 1,2‐diols with high selectivity factors. The kinetic resolution ofd,l‐hydrobenzoin andtrans‐1,2‐cyclohexanediol on a multigram scale (10 g) also proceeded with high selectivity and under moderate reaction conditions: (i) very low catalyst loading (0.1 mol%); (ii) an easily achievable low reaction temperature (0 °C); (iii) high substrate concentration (1.0 M); and (iv) short reaction time (30 min).