Gold Catalyzed Photoredox C1-Alkynylation of N-Alkyl-1,2,3,4- tetrahydroisoquinolines by 1-Bromoalkynes with UVA LED Light

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Abstract

A synthetic method that combines [Au2(m-dppm)2]Cl2 (dppm=bis(diphenylphosphanyl)methane) and UVA LED (LED=light emitting diode) light (365 nm) to catalyze the regioselective C1-alkynylation of N-alkyl-1,2,3,4-tetrahydroisoquinolines (THIQs) with alkynyl bromides is described. The reaction mechanism was delineated to involve a reductive quench pathway to generate the two posited radical species of the nitrogen-containing heterocycle and organic halide. In contrast, radical formation via an oxidative quench pathway was suggested to be operative in analogous control experiments with a 1-iodoalkyne. The usefulness of this carbon-carbon bond forming strategy was also exemplified by its application to the formal synthesis of the opioid analgesic drug methopholine and synthesis of a protoberberine alkaloid derivative.

Original languageEnglish
Pages (from-to)1313-1321
Number of pages9
JournalAdvanced Synthesis and Catalysis
Volume361
Issue number6
DOIs
Publication statusPublished - 1 Jan 2019

Keywords

  • Alkynylation
  • Gold
  • Homogeneous catalysis
  • Photoredox catalysis
  • Synthetic methods

Cite this

@article{690dc978bc9848f6a5bf9fd162f36001,
title = "Gold Catalyzed Photoredox C1-Alkynylation of N-Alkyl-1,2,3,4- tetrahydroisoquinolines by 1-Bromoalkynes with UVA LED Light",
abstract = "A synthetic method that combines [Au2(m-dppm)2]Cl2 (dppm=bis(diphenylphosphanyl)methane) and UVA LED (LED=light emitting diode) light (365 nm) to catalyze the regioselective C1-alkynylation of N-alkyl-1,2,3,4-tetrahydroisoquinolines (THIQs) with alkynyl bromides is described. The reaction mechanism was delineated to involve a reductive quench pathway to generate the two posited radical species of the nitrogen-containing heterocycle and organic halide. In contrast, radical formation via an oxidative quench pathway was suggested to be operative in analogous control experiments with a 1-iodoalkyne. The usefulness of this carbon-carbon bond forming strategy was also exemplified by its application to the formal synthesis of the opioid analgesic drug methopholine and synthesis of a protoberberine alkaloid derivative.",
keywords = "Alkynylation, Gold, Homogeneous catalysis, Photoredox catalysis, Synthetic methods",
author = "Yichao Zhao and Jianwen Jin and Chan, {Philip Wai Hong}",
year = "2019",
month = "1",
day = "1",
doi = "10.1002/adsc.201801289",
language = "English",
volume = "361",
pages = "1313--1321",
journal = "Advanced Synthesis and Catalysis",
issn = "1615-4150",
publisher = "Wiley-Blackwell",
number = "6",

}

TY - JOUR

T1 - Gold Catalyzed Photoredox C1-Alkynylation of N-Alkyl-1,2,3,4- tetrahydroisoquinolines by 1-Bromoalkynes with UVA LED Light

AU - Zhao, Yichao

AU - Jin, Jianwen

AU - Chan, Philip Wai Hong

PY - 2019/1/1

Y1 - 2019/1/1

N2 - A synthetic method that combines [Au2(m-dppm)2]Cl2 (dppm=bis(diphenylphosphanyl)methane) and UVA LED (LED=light emitting diode) light (365 nm) to catalyze the regioselective C1-alkynylation of N-alkyl-1,2,3,4-tetrahydroisoquinolines (THIQs) with alkynyl bromides is described. The reaction mechanism was delineated to involve a reductive quench pathway to generate the two posited radical species of the nitrogen-containing heterocycle and organic halide. In contrast, radical formation via an oxidative quench pathway was suggested to be operative in analogous control experiments with a 1-iodoalkyne. The usefulness of this carbon-carbon bond forming strategy was also exemplified by its application to the formal synthesis of the opioid analgesic drug methopholine and synthesis of a protoberberine alkaloid derivative.

AB - A synthetic method that combines [Au2(m-dppm)2]Cl2 (dppm=bis(diphenylphosphanyl)methane) and UVA LED (LED=light emitting diode) light (365 nm) to catalyze the regioselective C1-alkynylation of N-alkyl-1,2,3,4-tetrahydroisoquinolines (THIQs) with alkynyl bromides is described. The reaction mechanism was delineated to involve a reductive quench pathway to generate the two posited radical species of the nitrogen-containing heterocycle and organic halide. In contrast, radical formation via an oxidative quench pathway was suggested to be operative in analogous control experiments with a 1-iodoalkyne. The usefulness of this carbon-carbon bond forming strategy was also exemplified by its application to the formal synthesis of the opioid analgesic drug methopholine and synthesis of a protoberberine alkaloid derivative.

KW - Alkynylation

KW - Gold

KW - Homogeneous catalysis

KW - Photoredox catalysis

KW - Synthetic methods

UR - http://www.scopus.com/inward/record.url?scp=85066134859&partnerID=8YFLogxK

U2 - 10.1002/adsc.201801289

DO - 10.1002/adsc.201801289

M3 - Article

VL - 361

SP - 1313

EP - 1321

JO - Advanced Synthesis and Catalysis

JF - Advanced Synthesis and Catalysis

SN - 1615-4150

IS - 6

ER -