Radical Copolymerization of a Phosphaalkene with Styrene: New Phosphine‐Containing Macromolecules and Their Use in Polymer‐Supported Catalysis

Abstract

Since Beckers synthesis of the first stable phosphaalkene in 1976, [1] these compounds, which contain a P=C bond and were once considered exotic, now constitute a major branch of phosphorus chemistry. Applications for these compounds are even being developed.[2-4] The ability of P = C bonds, in many instances, to "copy" the well-established chemistry of isolobal C=C bonds has attracted considerable attention. [2, 3a, d] In molecular chemistry, the remarkable analogy between phosphaalkenes and alkenes is evidenced by phospha variants of a number of reactions, including 1,2-addition, [4+2]cycloaddition, Peterson and Wittig olefination, h 2 coordination to metal centers, and Cope and allylic rearrangements. One of the most important reactions of C = C bonds is the addition polymerization of olefins, which is used to produce many commodity polymers. The absence of an analogous polymer chemistry for P=C bonds prompted us to investigate addition polymerization as a potential route to new phosphine polymers. We recently reported the first addition polymerization of the phosphaalkene 1[5] (Mes = 2,4,6-trimethylphenyl) to give the poly(methylenephosphine) 2 (M w % 10 4 g mol À1 by GPC versus polystyrene), an alternating PÀC polymer. [6]

Homogenous Dual-Ligand Zinc Complex Catalysts for Chemical Fixation of CO2 to Propylene Carbonate

“…As seen, pressure has a great influence on the yield of PC upon varying the CO 2 pressure in the range 2.5-4.0 MPa, whereas the yield changes only slightly with [98 % selectivity in the range 4.0-5.0 MPa. A similar influence of CO 2 pressure on catalytic activity has been observed in other catalytic systems in the literature [41,42]. Based on the reports, PO and PC should be in their liquid form under the reaction conditions adopted.…”

Metallopolymers: New Multifunctional Materials

“…[161] Although the ratio of phosphaalkene in the feed was not reflected in the amount of phosphorus incorporated in the polymer, the results proved reproducible. One member of the series, when combined with [Pd 2 (dba) 3 ] (32, dba = dibenzylideneacetone) and CsF, was shown to be an effective catalyst for the Suzuki cross-coupling of bromobenzene with phenylboronic acid.…”

Erratum: Synthesis of functional phosphines with ortho‐substituted aryl groups: 2‐RC6H4PH2 and 2‐RC6H4P(SiMe3)2 (R = i‐Pr‐ or t‐Bu)

“…of a wide range of functional homopolymers, or block-or random-copolymers, that are effective in binding transition metals [25,26], forming selfassembled nanostructures, and as ligands for use in polymer-supported catalysts [27]. In addition, we have recently been interested in the development of phosphaalkene-based ligands for use in asymmetric catalysis (Scheme 2, II) [28,29].…”