Synthesis of Chiral C2‐Symmetric Bimetallic Zinc Complexes of Amido‐Oxazolinates and Their Application in Copolymerization of CO2 and Cyclohexene Oxide. Issue 12 (9th August 2016)

• Record Type: Journal Article
• Authors: Abbina, Srinivas; Chidara, Vamshi K.; Bian, Shi; Ugrinov, Angel; Du, Guodong
• Is Part Of: ChemistrySelect. Volume 1:Issue 12(2016)
• Page Start: 3175
• Page End: 3183
• Publication Date: 2016-08-09
• Subjects: Bimetallic Complexes -- Carbon dioxide -- Dizinc -- N, N-ligand -- Polycarbonate; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201600581
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: A family of new chiral C 2 symmetric amido‐oxazolinate ligands H2 L (1 a‐1 d ) that are bridged by three different linkers based on m ‐phenylenediamine, 4‐(4'‐aminobenzyl)benzenamine, and 1, 8‐diaminoanthracene have been synthesized in high yields (85‐90 %). Treatment of ligands (1 a‐1 d ) with two equiv. of Zn[N(SiMe3 )2 ]2 in dry toluene generated a series of heteroleptic dizinc complexes (L)[ZnN(SiMe3 )2 ]2 (2 a ‐2 d ) and reaction of1 b with one equiv. of Zn[N(SiMe3 )2 ]2 leads to formation of a homoleptic binuclear zinc complex (L)2 Zn2 (3 b ) in good yield. Complexes2 a ‐2 d were found to be effective catalysts for asymmetric alternating copolymerization of CO2 and cyclohexene oxide (CHO). The catalyst2 a is more active towards polycarbonate formation (78 % carbonate linkages), while the catalyst2 d generates highly isotactic poly(cyclohexene carbonate) (86 % of m ‐centered tetrads). Abstract : A series of chiral bimetallic zinc complexes have been synthesized, which are shown to be active in the copolymerization of CO2 and cyclohexene oxide.