P‐Stereogenic Optically Active Polymer and the Complexation Behavior

Abstract

The synthetic details of the P-stereogenic optically active polymer and the complexation behavior with palladium and platinum complexes are reported. The polymer consists of P-stereogenic bisphosphine units and the conjugated phenylene-ethynylene units alternately. The P-stereogenic bisphosphine moieties can coordinate to transition metals such as palladium and platinum, leading to a change in the conformation. optically active polymers. In a previous communication, we reported the synthesis of optically active polymers consisting of P-stereogenic bisphosphine and mphenylene-ethynylene units in the main chain by using ( S,S )-1 -BH 3 as a monomer and investigated the complexation with palladium. [ 40 ] In this article, we disclose the synthetic procedure of the P-stereogenic optically active poly mer and discuss the complexation behavior of the polymers with palladium and platinum in detail. Results and DiscussionThe synthesis of the key monomer ( S,S )-3 -BH 3 is outlined in Scheme 1 . Methyl groups in ( S,S )-1a -BH 3 can be readily lithiated thanks to the electron-withdrawing feature of the coordinated BH 3 . The treatment of ( S,S )-1 -BH 3 with sec -BuLi and N , N , N ′ , N ′ -tetramethylethylenediamine (TMEDA) in THF at -78 ° C provided the dilithiated intermediate, which was reacted in situ with 3-(bromomethyl)-1-iodobenzene at room temperature to obtain the corresponding P-stereogenic enantiomerically pure compound ( S,S )-3 -BH 3 in 59% isolated yield. The enantiomeric purity was maintained during the reactions, because the reactions do not include an asymmetric process. 3,5-Diethynyl-1-dodecyloxybenzene ( 7 ) was synthesized as a comonomer, as shown in Scheme 2 . The reaction of 3,5-dibromophenol ( 4 ) with 1-bromododecane in the presence of K 2 CO 3 in acetone afforded the 3,5-dibromo-1-dodecyloxybenzene ( 5 ) in 84% isolated yield. Sonogashira-Hagihara coupling [ 42 ] of 4 with trimethylsilylacetylene was carried out by a PdCl 2 (PPh 3 ) 2 /

Functional Polymeric Materials Based on Main‐Group Elements

“…[88] In addition, the LB character of the phosphine groups was employed in the coordination of antimony to form stibino-phosphonium and stibino-bis(phosphonium) functionalized polymer networks as precursors for ceramic materials. [90] Combination with other functional spacers,such as azobenzene, [91] 1,2,3-triazole, [92] and mphenylene-ethynylene units [93] provided responsiveness to UV-irradiation and allowed for deliberate conformational changes in the polymer chain (48). [90] Combination with other functional spacers,such as azobenzene, [91] 1,2,3-triazole, [92] and mphenylene-ethynylene units [93] provided responsiveness to UV-irradiation and allowed for deliberate conformational changes in the polymer chain (48).…”

Funktionelle polymere Materialien auf der Basis von Hauptgruppen‐Elementen

“…In einer verwandten Studie wurde das semi-immobilisierte Polyamin-Netzwerk 43 mit B(C 6 F 5 ) 3 gemischt und zur Hydrierung von Diethylbenzylidenmalonat eingesetzt. [90] Die Kombination mit anderen funktionellen Abstandhaltern, wie Azobenzol, [91] 1,2,3-Triazol [92] und m-Phenylen-Ethinylen-Einheiten, [93] führt zu einer Reaktionsfähigkeit gegenüber UV-Bestrahlung und ermçglicht eine gezielte Konformationsänderung in der Polymerkette (48 [96] Anfangs schlugen sie die Bildung von linearen Poly(methylenphosphanen) 49 (Abbildung 12) vor,d ie sich in Analogie zur Polymerisation von Olefinen [94,97] durch Kopf-Schwanz-Additionspolymerisation ergeben. [85] In einer eleganten, aktuellen Studie zeigten Ragogna et al,d ass Phosphan-En-Reaktionen einen alternativen Zugang zu P-haltigen Polymernetzwerken bieten.…”

Synthesis of unsymmetrical P-stereogenic oligophosphines and chemoselective cleavage of phosphine-borane coordinate bonds

“…We attempted to remove the boranes coordinated with the phosphorus atoms in tetraphosphine (S,R,R,S)-8 ÀBH 3 by using organic bases such as morpholine 23 [11][12][13] ). When (S,R,R,S)-8 ÀBH 3 was stirred in morpholine for 48 h, all the boranes were readily removed.…”

“…[2][3][4][5][6] However, despite the widespread use of P-stereogenic phosphines, polymers containing chiral phosphorus atoms in their backbones have rarely been prepared. 7 Recently, we synthesized P-stereogenic optically active polymers [8][9][10][11][12][13] and oligomers [14][15][16] using P-stereogenic bisphosphines as chiral building blocks. These molecules formed higher-ordered chiral structures derived from P-stereogenic centers, and their conformations could be controlled through metal coordination with bisphosphine moieties.…”

“…These molecules formed higher-ordered chiral structures derived from P-stereogenic centers, and their conformations could be controlled through metal coordination with bisphosphine moieties. [11][12][13] On the other hand, well-defined oligophosphines could potentially be used as platforms for binding transition metals in an orderly fashion. Several types of optically active P-stereogenic oligophosphines have already been prepared ( Figure 1).…”