Structure and isomerization behavior relationships of new push-pull azo-pyrrole photoswitches.

A family of stilbenyl-azopyrroles compounds 2a-d and 3a-d was efficiently obtained a Mizoroki-Heck C-C-type coupling reaction between 2-(4'-iodophenyl-azo)--methyl pyrrole (1a) and different vinyl precursors. The influence of the π-conjugated backbone and the effect of the pyrrole moiety were correlated with their optical properties. Studies UV-Visible spectrophotometry revealed that the inclusion of EWG or EDG favors a red-shift of the main absorption band in these azo compounds compared with their non-substituted analogues.

Well-defined Cu(I) complexes based on [N,P]-pyrrole ligands catalyzed a highly endoselective 1,3-dipolar cycloaddition.

We herein report the synthesis and catalytic application of a new family of dinuclear Cu(I) complexes based on [N,P]-pyrrole ligands. The Cu(I) complexes (4a-d) were obtained in good yields and their catalytic properties were evaluated in the1,3-dipolar cycloaddition of azomethine ylides and electron-deficient alkenes. The air-stable complexes 4a-d exhibited high endo-diasteroselectivity to obtain substituted pyrrolidines, and the catalytic system showed excellent reactivity and wide substitution tolerance.

Pharmacokinetic assessment and phytochemical triterpene control from Cecropia angustifolia using plant biotechnology.

Introduction: Cecropia angustifolia Trécul. is a native Andean plant containing high levels of pentacyclic triterpenes (PTs), including several isobaric molecules that serve as chemical markers. Preclinical studies suggest that PTs positively modulate metabolic and vascular diseases.

Two-photon isomerization properties of donor-acceptor Stenhouse adducts.

Donor-acceptor Stenhouse adducts (DASAs) are important photo-responsive molecules that undergo electrocyclic reactions after light absorption. From these properties, DASAs have received extensive attention as photo-switches with negative photochromism. Meanwhile, several photochemical applications require isomerization events to take place in highly localized volumes at variable depths.

Synthesis of (μ,η-allyl-η-oxapentadienyl)diiron pentacarbonyl complexes, an unusual reaction product from η-(vinylketene)Fe(CO) complexes: structure and electron density distribution analysis.

The synthesis of a series of ferrocenylvinylketenes as stable η-[Fe(CO)] complexes (3a-f) was successfully accomplished through the reaction of η-[Fe(CO)] complexes under mild carbonylation conditions. The reactivity of 3a-f under thermal conditions afforded the unexpected formation of a novel family of (μ,η-allyl-η-oxapentadienyl)diiron pentacarbonyl complexes 5a-f proposed to be formed by a sequence metathesis-haptotropic rearrangement between the starting η-vinylketene iron(0) complex 3 and a η-vinylcarbene iron(0) complex trapped after a reversible carbonylation process favored by the thermal conditions. An electron density distribution analysis (EDD) of 5e using high-resolution X-ray diffraction data in combination with the DFT framework was performed to understand the electronic communication between the two iron fragments.