Use of -methyliminodiacetic acid boronate esters in suzuki-miyaura cross-coupling polymerizations of triarylamine and fluorene monomers.

Polytriarylamine copolymers can be prepared by Suzuki-Miyaura cross-coupling reactions of bis -methyliminodiacetic acid (MIDA) boronate ester substituted arylamines with dibromo arenes. The roles of solvent composition, temperature, reaction time, and co-monomer structure were examined and (co)polymers prepared containing 9, 9-dioctylfluorene (F8), 4-sec-butyl or 4-octylphenyl diphenyl amine (TFB), and , '-bis(4-octylphenyl)-, '-diphenyl phenylenediamine (PTB) units, using a Pd(OAc)/2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (SPhos) catalyst system. The performance of a di-functionalized MIDA boronate ester monomer was compared with that of an equivalent pinacol boronate ester.

Chemically synthesized and cross-linked PDMS as versatile alignment medium for organic compounds.

A useful procedure for the preparation of chemically synthesized and cross-linked polydimethylsiloxane (PDMS) gels is presented, which does not require β-irradiation for cross-linking. NMR spectra of high quality are obtained, such that even mixtures of compounds exhibiting similar NMR spectra like interconverting stereoisomers can be investigated in the residual dipolar coupling (RDC) approach of organic structure determination.

Dynamic behaviour of monohaptoallylpalladium species: internal coordination as a driving force in allylic alkylation chemistry.

Contemporary catalytic procedures involving alkylpalladium(ii) have enriched the arsenal of synthetic organic chemistry. Those transformations usually rely on internal coordination through "directing groups", carefully designed to maximize catalytic efficiency and regioselectivity. Herein, we report structural and reactivity studies of a series of internally coordinated monohaptoallylpalladium complexes.

Mechanistic studies into amine-mediated electrophilic arene borylation and its application in MIDA boronate synthesis.

Direct electrophilic borylation using Y(2)BCl (Y(2) = Cl(2) or o-catecholato) with equimolar AlCl(3) and a tertiary amine has been applied to a wide range of arenes and heteroarenes. In situ functionalization of the ArBCl(2) products is possible with TMS(2)MIDA, to afford bench-stable and easily isolable MIDA-boronates in moderate to good yields. According to a combined experimental and computational study, the borylation of activated arenes at 20 °C proceeds through an S(E)Ar mechanism with borenium cations, [Y(2)B(amine)](+), the key electrophiles.

Towards click bioconjugations on cube-octameric silsesquioxane scaffolds.

Cube-octameric silsesquioxane (POSS) based conjugation scaffolds for copper catalysed azide-alkyne [3+2] cycloaddition are reported. The synthetic route to octaazido and octaalkyno functionalised POSS templates without cage rearrangements is described. A set of click couplings is conducted including the first effective conjugation with a fully unprotected functional peptide towards a POSS assembled peptide octamer.

Enantiodivergent conversion of chiral secondary alcohols into tertiary alcohols.

From receptors in the nose to supramolecular biopolymers, nature shows a remarkable degree of specificity in the recognition of chiral molecules, resulting in the mirror image arrangements of the two forms eliciting quite different biological responses. It is thus critically important that during a chemical synthesis of chiral molecules only one of the two three-dimensional arrangements is created. Although certain classes of chiral molecules (for example secondary alcohols) are now easy to make selectively in the single mirror image form, one class-those containing quaternary stereogenic centres (a carbon atom with four different non-hydrogen substituents)-remains a great challenge.