Abstract The synthesis of alicyclic 2-methylenethiazolo[2,3-b]quinazo­l­inones is performed via base-promoted cascade reactions, starting from either β-amino propargylamides using carbon disulfide, or ethyl 2-isothiocyanatocarboxylates by addition propargylamine. In both cases the reaction proceeds way a favoured 5-exo-dig process during second ring closure, as confirmed full NMR spectroscopic ...

The first exclusive regioselective fragmentation of primary ozonides controlled by remote carbonyl groups on ozonolysis of norbornene derivatives and reaction of final ozonides with triethylamine as a new probe for determining the regiochemistry of carbonyl oxide formation from primary ozonide fragmentation are reported. Ozonolysis of the endo adducts 3a-d and the deuterated compounds 8a and 8b...

Ring-opening metathesis polymerization (ROMP) is one of the most widely used polymerizations. With the development of well-defined catalysts, such as (t-BuO)2(ArN)Mo=CH(t-Bu) (1), Cl2(PCy3)2Ru=CHPh (2), and Cl2(PCy3)(IMesH2)Ru=CHPh (3), more controlled polymer structures have been obtained by either living polymerization or chain transfer induced polymerization. However, these catalysts suffer ...

A series of bis(β-ketoamino) titanium complexes containing pyrazolone rings (1–3) have been synthesized, characterized, and used as precursors for homoand copolymerization of ethylene and norbornene. The titanium complexes activated with methylaluminoxane (MAO) exhibited good activities for homopolymerization of ethylene (E) to produce linear polyethylenes (PEs). Ethylene–norbornene copolymers ...

We describe the parallel, one-pot synthesis of core-photocleavable, poly(norbornene)-co-poly(ethylene glycol) (PEG) brush-arm star polymers (BASPs) via a route that combines the "graft-through" and "arm-first" methodologies for brush polymer and star polymer synthesis, respectively. In this method, ring-opening metathesis polymerization of a norbornene-PEG macromonomer generates small living br...

[reaction: see text] Norbornene undergoes Ni-catalyzed (1-2 mol% allylnickel bromide/phosphine/NaBARF or AgSbF(6), 1 bar ethylene, -50 degrees C) hydrovinylation (>97% yield), giving either a 1:1 or a 2:1 (norbornene/ethylene) adduct depending on the size of the phosphine. Use of binaphthol-derived phosphoramidite ligand results in up to 80% ee for the 1:1 adduct. The course of the reaction is ...

Amphiphilic norbornene-b-(norbornene dicarboxylic acid) diblock copolymers with different block ratios were prepared as templates for the incorporation of iron ions using an ion exchange protocol. The disordered arrangement of iron oxide particles within these copolymers was attributed to the oxidation of the iron ions and the strong interactions between iron oxide nanoparticles, particularly a...

We present a bioorthogonal and modular conjugation method for efficient coupling of organic dyes and biomolecules to quantum dots (QDs) using a norbornene-tetrazine cycloaddition. The use of noncoordinating functional groups combined with the rapid rate of the cycloaddition leads to highly efficient conjugation. We have applied this method to the in situ targeting of norbornene-coated QDs to li...

A novel method for preparing α-norbornene methylene polystyrene macromonomer (NBMPSt) is reported. NBMPSt macromonomer ( Mn = 1.60 × 10 and PDI = 1.26) had glass transition temperature (Tg) of 107 C for polystyrene segment. Since the homopolymerization of NBMPSt macromonomer with number average molecular weight ( Mn ) 1.60 ×10 could not be carried out by ring-opening metathesis polymerization (...