Stereocontrolled Synthesis and Photoisomerization Behavior of All-Cis and All-Trans Poly(m-phenylenevinylene)s

Abstract

All-cis and all-trans isomers of poly[(arylenevinylene)-alt-(5-octyloxy-1,3-phenylenevinylene)]s having three kinds of arylene groups (PmPVs: arylene = m-phenylene (1a), p-phenylene (1b), 4,4 0 -biphenylene (1c)) have been synthesized in almost perfect stereoregularity by two types of palladium-catalyzed polycondensation reactions, respectively. Suzuki-Miyaura-type polycondensation of (Z,Z)-bis(2-bromoethenyl)arenes with 5-octyloxy-1,3-benzenediboronic acid pinacolate affords all-cis 1a-c, whereas Hiyama-type polycondensation of (E,E)-bis(2-silylethenyl)arenes with 5-octyloxy-1,3-diiodobenzene forms all-trans 1a-c. The resulting polymers with relatively short effective π-conjugation lengths interrupted by mphenylene units undergo two-way photoisomerization to give PmPVs containing cis-and trans-vinylene groups in nearly 1:1 ratios irrespective of the arylene groups of staring polymers.

Analysis of diverse direct arylation polymerization (DArP) conditions toward the efficient synthesis of polymers converging with stille polymers in organic solar cells

“…Lastly, the final two DArP conditions continue to feature phosphine ligands but from protocols derived from Ozawa et al 45 Both Leclerc et al and Ozawa et al have shown success with P(o-NMe 2 Ph 3 ) 3 as an effective ligand for the synthesis of defect-free copolymers. 11,60 Through the incorporation of two ligands, P(o-NMe 2 Ph 3 ) 3 and P(o-anisyl) 3 , Ozawa et al produced copolymers based on dithienosilole and thienopyrroledione without defects. 61 Despite the success of the dual ligand approach, P(o-anisyl) 3 has been successfully incorporated into different catalytic systems as the lone ligand.…”

A Defect‐Free Naphthalene Diimide Bithiazole Copolymer via Regioselective Direct Arylation Polycondensation

“…[10,[15][16][17] With these advantageous properties, BTz became an interesting building block for materials with applications in organic field-effect transistors (OFETs) and organic photovoltaics (OPVs). [12,13,16,18] From a synthetic point of view, state-of-the-art Stille or Suzuki polycondensations have been mostly applied to prepare BTz- [11,[19][20][21] and also NDI-based [1,4] polymers. These synthetic transformations are currently being replaced by in many ways more attractive C-H functionalization strategies.…”

Cross‐Coupling Reactions of Organosilicon Compounds in the Stereocontrolled Synthesis of Retinoids

“…A solution of trienyl iodides 6 or 6' (1.0 equiv) in THF and [Pd 2 A C H T U N G T R E N N U N G (dba) 3 ]·CHCl 3 (0.05-0.1 equiv) were sequentially added at RT, and the mixture was stirred for 1 h. Diethyl ether was added and the mixture was filtered through a short pad of silica gel. The solvent was removed under vacuum and the crude mixture was purified by column chromatography (SiO 2 , 95:5 hexane/AcOEt) to afford the corresponding retinyl ethers (15)(16)(17)(18)(19)(20)(21)(22) as yellow oils. Silylhydride coupling: By following the general procedure, treatment of a solution of silylhydride 8 e (28 mg, 0.096 mmol) in THF (2 mL) with TBAF (1.0 m in THF, 96 mL, 0.96 mmol) for 30 min at 0 8C, followed by addition of a solution of iodide 6 (15 mg, 0.05 mmol) in THF (1 mL) and [Pd 2 A C H T U N G T R E N N U N G (dba) 3 ]·CHCl 3 (2 mg, 0.002 mmol) afforded compound 18 in 85 % yield (15 mg).…”

“…Furthermore, the scope of the reaction has been extended by the advent of “safety‐catch” silanols,15 which are stable under conditions that heteroatom‐substituted silanes may not tolerate, but which can nonetheless be activated for cross‐coupling in situ. Hiyama cross‐coupling is now a well‐established methodology for the synthesis of organic materials16 and complex natural products 14l…”