AUTHOR=Yu Heesun , Kim Hyoungsu , Baek Seung-Hoon , Lee Dongjoo 

TITLE=Direct and Efficient C(sp3)–H Functionalization of N-Acyl/Sulfonyl Tetrahydroisoquinolines (THIQs) With Electron-Rich Nucleophiles via 2,3-Dichloro-5,6-Dicyano-1,4-Benzoquinone (DDQ) Oxidation

JOURNAL=Frontiers in Chemistry

VOLUME=8

YEAR=2020

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2020.00629

DOI=10.3389/fchem.2020.00629

ISSN=2296-2646

ABSTRACT=<p>A highly efficient metal-free oxidative direct C(sp<sup>3</sup>)–H functionalization of <italic>N</italic>-acyl/sulfonyl 1,2,3,4-tetrahydroisoquinolines (THIQs) with a wide range of electron-rich nucleophiles was accomplished under mild conditions through oxidation with DDQ and subsequent trapping of the resulting reactive and stable <italic>N</italic>-acyl/sulfonyl iminium ions. The synthetic utility of this method was illustrated by a concise and efficient total synthesis of (±)-benzo[<italic>a</italic>]quinolizidine (<bold>10</bold>) in 3 steps from the known <italic>N</italic>-Cbz 1,2,3,4-THIQ <bold>4b</bold>.</p>