26234-46-8Relevant articles and documents
Synthesis and structural characterization of N-Phenyl-5-norbornene-2,3-dicarboximide
Liang, Zu Pei,Li, Jian,Pan, Xiao Ru
, p. 2806 - 2808 (2015)
The compound N-phenyl-5-norbornene-2,3-dicarboximide (C15H13NO2, Mr = 239.26) was synthesized and characterized by single crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/c, with a = 9.7534(13), b = 21.395(2), c = 12.0647(14) ?, β = 108.7020(10)°, V = 2384.6(5) ?3, Z = 8, Dc = 1.333 g/cm3, λ = 0.71073 ?, μ(MoKα) = 0.089 mm-1, F(000) = 1008. The final refinement gave R = 0.0741, wR (F2) = 0.1676 for 4,199 observed reflections with I > 2α(I). The structure of the title compound comprises a racemic mixture of chiral molecules containing four stereogenic centres. X-ray diffraction analysis reveals that the cyclohexane ring tends towards a boat conformation, the tetrahydrofuran ring and the dihydrofuran ring adopt envelope conformations. The dihedral angles between the pyrrolidine-2,5-dione plane and the aromatic ring are 65.5 (2)° and 54.9 (2)°, respectively in the two molecules.
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Baldwin et al.
, p. 5249 (1970)
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Novel crossed Diels-Alder reactions of 1-(2-butadienyl)pyridinium bromide
Lee, Shwu-Jiuan,Tzeng, Chiou-Bih,Lin, Su-Ching,Chao, Ito,Lu, Hsiu-Feng,Chou, Ta-Shue
, p. 9293 - 9296 (1996)
Crossed Diels-Alder cycloadditions of a positively charged diene, 1-(2-butadienyl)pyridinium bromide (1a), with cyclopentadiene in acetonitrile proceed stereospecifically and regioselectively. The regioselectivity of 1a as the dienophile is especially unique.
Synthesis and characterization of exo-endo and endo-endo benzenesulfonylaziridines
Da Silva Andrade, Evilazio,Nunes, Ricardo Jose,Uieara, Marina
, p. 3073 - 3081 (2004)
In the search for structural cyclic imide analogues of therapeutic interest, the synthesis, separation, and characterization of exo-endo 3 and endo-endo 4 stereoisomers of benzenesulfonylaziridines, not found in the literature, are described in this study
Catalytic Living Ring Opening Metathesis Polymerisation: The Importance of Ring Strain in Chain Transfer Agents
Liu, Peng,Yasir, Mohammad,Kilbinger, Andreas F. M.
, p. 15278 - 15282 (2019/09/17)
A recently developed catalytic living ring opening metathesis polymerisation (ROMP) was investigated using a series of reversible chain transfer agents (CTA) carrying either cyclopentene or cyclohexene rings, differing only in ring strain. All cyclopentene derivatives examined showed significantly faster reaction rates than the corresponding cyclohexene derivatives. This resulted in lower molecular weight dispersities and better control of the molecular weight for the cyclopentene compared to the cyclohexene CTAs. Both Grubbs’ second and third generation catalysts could be employed in catalytic living ROMP using cyclopentene CTA derivatives. The kinetics of different CTAs were studied, block copolymers were synthesised and residual ruthenium quantified by ICP-OES. All polymers were fully characterised by NMR, GPC and MALDI-ToF mass spectrometry. The new cyclopentene CTAs are readily synthesised in a few straightforward steps and provide faster reaction kinetics than all previously reported reversible CTAs.
Design, Synthesis, and Self-Assembly of Polymers with Tailored Graft Distributions
Chang, Alice B.,Lin, Tzu-Pin,Thompson, Niklas B.,Luo, Shao-Xiong,Liberman-Martin, Allegra L.,Chen, Hsiang-Yun,Lee, Byeongdu,Grubbs, Robert H.
supporting information, p. 17683 - 17693 (2017/12/15)
Grafting density and graft distribution impact the chain dimensions and physical properties of polymers. However, achieving precise control over these structural parameters presents long-standing synthetic challenges. In this report, we introduce a versatile strategy to synthesize polymers with tailored architectures via grafting-through ring-opening metathesis polymerization (ROMP). One-pot copolymerization of an ω-norbornenyl macromonomer and a discrete norbornenyl comonomer (diluent) provides opportunities to control the backbone sequence and therefore the side chain distribution. Toward sequence control, the homopolymerization kinetics of 23 diluents were studied, representing diverse variations in the stereochemistry, anchor groups, and substituents. These modifications tuned the homopolymerization rate constants over 2 orders of magnitude (0.36 M-1 s-1 homo -1 s-1). Rate trends were identified and elucidated by complementary mechanistic and density functional theory (DFT) studies. Building on this foundation, complex architectures were achieved through copolymerizations of selected diluents with a poly(d,l-lactide) (PLA), polydimethylsiloxane (PDMS), or polystyrene (PS) macromonomer. The cross-propagation rate constants were obtained by nonlinear least-squares fitting of the instantaneous comonomer concentrations according to the Mayo-Lewis terminal model. In-depth kinetic analyses indicate a wide range of accessible macromonomer/diluent reactivity ratios (0.08 1/r2 20), corresponding to blocky, gradient, or random backbone sequences. We further demonstrated the versatility of this copolymerization approach by synthesizing AB graft diblock polymers with tapered, uniform, and inverse-tapered molecular "shapes." Small-angle X-ray scattering analysis of the self-assembled structures illustrates effects of the graft distribution on the domain spacing and backbone conformation. Collectively, the insights provided herein into the ROMP mechanism, monomer design, and homo- and copolymerization rate trends offer a general strategy for the design and synthesis of graft polymers with arbitrary architectures. Controlled copolymerization therefore expands the parameter space for molecular and materials design.
