用于氮杂环卡宾催化的烯醛与醛的不对称高烯醇交叉环化反应的烯醛的化学选择性极性反转

Chemoselective Umpolung of Enals for Asymmetric Homoenolate Cross-Annulation of Enals and Aldehydes Catalyzed by N-Heterocyclic Carbene.

作者信息

Ide Ryuji, Kyan Ryuji, Phuc Le Thien, Kitagawa Yuya, Sato Kohei, Mase Nobuyuki, Narumi Tetsuo

机构信息

Course of Applied Chemistry and Biochemical Engineering, Department of Engineering, Graduate School of Integrated Science and Technology , Shizuoka University , 3-5-1 Johoku , Hamamatsu , Shizuoka 432-8561 , Japan.

Graduate School of Science and Technology , Shizuoka University , 3-5-1 Johoku , Hamamatsu , Shizuoka 432-8561 , Japan.

出版信息

Org Lett. 2019 Nov 15;21(22):9119-9123. doi: 10.1021/acs.orglett.9b03509. Epub 2019 Nov 5.

DOI:10.1021/acs.orglett.9b03509

PMID:31686515

Abstract

An asymmetric homoenolate cross-annulation of enals and aldehydes with high enantioselectivity is realized by NHC-catalyzed chemoselective umpolung of enals. The reaction proceeds in a highly chemoselective manner, selectively generating the conjugated Breslow intermediates from enals rather than aldehydes, enabling the homoenolate addition of enals to aldehydes in preference to competing acyl anion-mediated reactions. Enantioenriched substituted γ-butyrolactones are formed in good yields with high enantioselectivities.

摘要

通过氮杂环卡宾催化烯醛的化学选择性极性反转，实现了烯醛与醛的不对称高对映选择性同烯醇化物交叉环化反应。该反应以高度化学选择性的方式进行，从烯醛而非醛中选择性地生成共轭布雷斯洛中间体，使得烯醛优先于竞争性的酰基阴离子介导反应向醛进行同烯醇化物加成。对映体富集的取代γ-丁内酯以良好的产率和高对映选择性生成。