Formation of Enamines via Catalytic Dehydrogenation by Pincer-Iridium Complexes

Yansong J. Lu, Xiawei Zhang, Santanu Malakar, Karsten Krogh-Jespersen, Faraj Hasanayn, Alan S. Goldman

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Di-isopropylphosphino-substituted pincer-ligated iridium catalysts are found to be significantly more effective for the dehydrogenation of simple tertiary amines to give enamines than the previously reported di-t-butylphosphino-substituted species. It is also found that the di-isopropylphosphino-substituted complexes catalyze dehydrogenation of several β-functionalized tertiary amines to give the corresponding 1,2-difunctionalized olefins. The di-t-butylphosphino-substituted species are ineffective for such substrates; presumably, the marked difference is attributable to the lesser crowding of the di-isopropylphosphino-substituted catalysts. Experimentally determined kinetic isotope effects in conjunction with DFT-based analysis support a dehydrogenation mechanism involving initial pre-equilibrium oxidative addition of the amine α-C-H bond followed by rate-determining elimination of the β-C-H bond.

Original languageEnglish
Pages (from-to)3020-3028
Number of pages9
JournalJournal of Organic Chemistry
Volume85
Issue number5
DOIs
Publication statusPublished - Mar 6 2020

ASJC Scopus subject areas

  • Organic Chemistry

Fingerprint Dive into the research topics of 'Formation of Enamines via Catalytic Dehydrogenation by Pincer-Iridium Complexes'. Together they form a unique fingerprint.

  • Cite this