Stereochemical Control via Chirality Pairing: Stereodivergent Syntheses of Enantioenriched Homoallylic Alcohols
Stereochemical Control via Chirality Pairing: Stereodivergent Syntheses of Enantioenriched Homoallylic Alcohols
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DOI：
10.1002/anie.202107004
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发表时间：
2021-10-04
影响因子：
16.6
通讯作者：
Chen, Ming
中科院分区：
文献类型：
--
作者：
Gao, Shang;Duan, Meng;Chen, Ming
本文报道了利用手性非外消旋α-CH（2）Bpin取代巴豆基硼酸酯立体分散合成对映体富集的高烯丙醇。手性磷酸（S）-A催化的烯丙基不对称加成反应得到了具有良好的对映选择性和Z-选择性的Z-反高烯丙基醇。当使用对映体酸催化剂（R）-A时，立体选择性完全逆转，得到具有高E-选择性和优异的对映体选择性的E-反式高烯丙醇。通过硼试剂的手性与催化剂的配对，可以从同一个硼试剂中选择性地得到手性高烯丙醇的两个互补立体异构体。DFT计算研究进行了探测所观察到的立体选择性的起源。这些反应产生高度对映体富集的高烯丙醇产物，其对于快速构建聚酮化合物结构框架是有价值的。
We report herein the development of stereodivergent syntheses of enantioenriched homoallylic alcohols using chiral nonracemic alpha-CH(2)Bpin-substituted crotylboronate. Chiral phosphoric acid (S)-A-catalyzed asymmetric allyl addition with the reagent gave Z-anti-homoallylic alcohols with excellent enantioselectivities and Z-selectivities. When the enantiomeric acid catalyst (R)-A was utilized, the stereoselectivity was completely reversed and E-anti-homoallylic alcohols were obtained with high E-selectivities and excellent enantioselectivities. By pairing the chirality of the boron reagent with the catalyst, two complementary stereoisomers of chiral homoallylic alcohols can be obtained selectively from the same boron reagent. DFT computational studies were conducted to probe the origins of the observed stereoselectivity. These reactions generate highly enantioenriched homoallylic alcohol products that are valuable for rapid construction of polyketide structural frameworks.