Shuttling Catalyst: Facilitating C−C Bond Formation via Cross‐Couplings with a Thermoresponsive Polymeric Ligand. Issue 3 (27th December 2019)

• Record Type: Journal Article
• Authors: Wang, Erfei; Zhang, Jiawei; Zhong, Zhuoran; Chen, Kaixuan; Chen, Mao
• Is Part Of: Israel journal of chemistry. Volume 60:Issue 3/4(2020)
• Page Start: 419
• Page End: 423
• Publication Date: 2019-12-27
• Subjects: polymeric ligand -- C−C bond formation -- sustainable chemistry -- biphasic catalysis -- synthetic methods; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/ijch.201900143
• Languages: English
• ISSNs: 0021-2148

Abstract

Abstract: A poly(ethylene glycol) (PEG) linked ortho ‐MeO‐phenyldicyclohexylphosphine (MeO‐WePhos) ligand has been synthesized to promote Pd‐catalyzed carbon‐carbon bond formation by cross‐couplings including Sonogashira, Heck, Hiyama and Stille reactions, providing corresponding (hetero)aryl substituted alkynes, alkenes and bi(hetero)aryls in good to excellent isolated yields with low Pd loadings. Facilitated by the lower critical solution temperature behaviour of the polymeric monophosphine ligand, the metal‐complex could rapidly shuttle between organic and water phases as regulated by temperature, enabling highly efficient catalyst recycling via a simple phase separation. The chemical structure of ligand was determined by matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry, nuclear magnetic resonance spectrometry and size‐exclusion chromatography measurements. Notably, as demonstrated by the inductively coupled plasma‐atomic emission spectrometry measurement, 98% Pd was kept in the water phase after 6 cycles of catalyst recycling experiments. Given the profound impact of transition‐metal‐catalyzed covalent bond formation and the increasing demand of sustainable chemistry, this work provides an alternative method to conduct cross‐couplings with a polymeric shuttling catalyst. Abstract :