Mixed‐Ligand Mandelato‐Phosphine Copper(I) Complexes as Active Catalysts in Carbene Transfer Reactions. Issue 26 (8th July 2022)

• Record Type: Journal Article
• Authors: Cinco, Anita; Colombo, Gioele; Brenna, Stefano; Therrien, Bruno; Ardizzoia, G. Attilio
• Is Part Of: ChemistrySelect. Volume 7:Issue 26(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-07-08
• Subjects: homogeneous catalysis -- hydroxycarboxylate -- carbene transfer -- copper -- phosphine; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.202202216
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: Two mixed ligand copper(I) complexes, [Cu(PPh3 )3 ( κ ‐O‐mand)] (CuP3M ) and [Cu(PPh3 )2 ( κ 2 ‐O, O'‐mand)] (CuP2M ) (mand=dl ‐mandelate) were synthesized and fully characterized. The different coordination modes of the α‐hydroxycarboxylate ligand in CuP2M and CuP3M are clearly demonstrated by infrared spectroscopy, with the asymmetric νC=O stretching being observed at 1626 (CuP3M ) and 1593 (CuP2M ) cm −1, respectively. Solution NMR studies ( 1 H, 31 P{ 1 H}), elemental and X‐ray structure analyses confirmed the nature of the synthesized compounds. Complexes CuP2M and CuP3M were active in carbene transfer reactions towards unsaturated bonds, using ethyl diazoacetate (N2 CHCOOEt, EDA) as carbene source. Indeed, they promoted the trans ‐diastereoselective cyclopropanation of terminal and internal olefins under mild reaction conditions and low catalyst loading (1 % mol). Abstract : Two easily‐prepared copper(I) mandelato complexes have been synthesized and their activity as homogenous catalysts has been investigated in carbene transfer reactions. In particular, conversions up to 90 % and trans diastereoselectiviy up to 96 % were reached in olefin cyclopropanation. Steric and electronic effects have been evaluated as well in competitive experiments.