Synthesis of Six-Membered Spiro Azacyclic Oxindole Derivatives via a One-Pot Process of Umpolung Allylation/Aza-Prins Cyclization

Woo Cheol Jang; Myeongjin Jung; Haye Min Ko

doi:10.1021/acs.orglett.1c00292

Synthesis of Six-Membered Spiro Azacyclic Oxindole Derivatives via a One-Pot Process of Umpolung Allylation/Aza-Prins Cyclization

Org Lett. 2021 Feb 19;23(4):1510-1515. doi: 10.1021/acs.orglett.1c00292. Epub 2021 Feb 9.

Authors

Woo Cheol Jang¹, Myeongjin Jung¹, Haye Min Ko^{1

2}

Affiliations

¹ Department of Chemistry, Wonkwang University, 460 Iksandae-ro, Iksan, Jeonbuk 54538, Republic of Korea.
² Wonkwang Institute of Materials Science and Technology, Wonkwang University, 460 Iksandae-ro, Iksan, Jeonbuk 54538, Republic of Korea.

PMID: 33560126
DOI: 10.1021/acs.orglett.1c00292

Abstract

An unprecedented synthetic approach involving umpolung allylation/aza-Prins cyclization of N-2,2,2-trifluoroethylisatin ketimines is described. The reactions proceed smoothly with allyl bromide in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene, H₂O, and trimethylsilyl bromide; this one-pot protocol allows access to six-membered spiro azacyclic oxindole derivatives in good to excellent yields. Notably, while the general aza-Prins cyclization involves amines and aldehydes, the present synthetic strategy represents the first aza-Prins cyclization that utilizes the umpolung property of N-2,2,2-trifluoroethylisatin ketimines.

Publication types

Research Support, Non-U.S. Gov't