Lewis Pair Polymerization of Alkyl Methacrylate by Amidinato Silicon Compounds and Tris(pentafluorophenyl)borane. Issue 13 (1st April 2022)

• Record Type: Journal Article
• Authors: Chia, Cher‐Chiek; Li, Yan; Xiao, Longqiang; Yang, Ming‐Chung; Su, Ming‐Der; So, Cheuk‐Wai
• Is Part Of: European journal of organic chemistry. Volume 2022:Issue 13(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-01
• Subjects: Boranes -- Carbene homologues -- Methacrylate -- Polymerization -- Silicon; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.202200003
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: 0.5 mol% of the amidinato disilyne [LSi:]2 (1, L=PhC(N t Bu)2 ) and 1 mol% of B(C6 F5 )3 cooperatively polymerized methyl methacrylate (MMA) to form poly(MMA) with the H and CH2 C(=CH2 )COMe end groups (P1, Mn =3.1×10 3 gmol −1 ; repeating unit, n=31; polydispersity index, Đ: 1.55). The catalytic mechanism is proposed, where compound 1 could react with MMA and B(C6 F5 )3 to form a zwitterionic active species [LSi{CH2 C(Me)=C(OMe)O}B(C6 F5 )3 ]2 . The latter could activate MMA molecules affording poly(MMA) chains on the silicon centers. The methyl group of the last enolate of a poly(MMA) chain on a silicon center could then react with the Si−C bond of the adjacent poly(MMA) chain to form P1, as well as regenerate compound 1 and B(C6 F5 )3 . When compound 1 was replaced by the amidinato amidosilylene [LSiN(SiMe3 )2 ] (2 ), 1 mol% of compound 2 and 1 mol% of B(C6 F5 )3 mediated living MMA polymerization in toluene to form the poly(MMA) P2 (Mn =1.04×10 4 gmol −1 ; Đ: 1.97). Abstract : A Lewis pair of the amidinato disilyne and B(C6 F5 )3 polymerized methyl methacrylate to form the polymer comprising H and CH2 C(=CH2 )CO2 Me end groups.