34312-77-1Relevant articles and documents
Nonlinear optical properties of novel thiophene derivatives: Experimental and ab initio time-dependent coupled perturbed Hartree-Fock studies
Karna, Shashi P.,Zhang, Yue,Samoc, Marek,Prasad, P. N.,Reinhardt, Bruce A.,Dillard, Ann G.
, p. 9984 - 9993 (1993)
We report in this paper experimental and theoretical studies of the nonlinear optical properties of a new class of compounds which differ from traditional second-order molecules in the sense that a commonly used electron donor chromophore is replaced by a thiophene ring.The molecular second-order nonlinear optical coefficients, β, is determined by the electric field-induced second-harmonic generation technique, for 2-nitro-1-(2-thienyl)ethene and 4-nitro-1-(2-thienyl)-1,3-butadiene are, respectively, 1 and 3 times that of para-nitroaniline.Ab initio time-dependent coupled perturbed Hartree-Fock results are in agreement with the experimental findings.A Mulliken population analysis indicates that the sulfur atom in the thiophene ring acts as an electron donor.Both the experimental and the theoretical results confirm that a thiophene ring acts as an efficient donor, giving rise to highly efficient second-order nonlinear optical properties.We also show that with this type of chromophore one can use a thiophene oligomer, in place of a thiophene monomer, to amplify the nonlinearity.
Palladium-Catalyzed Formal (3 + 2) Cycloaddition Reactions of 2-Nitro-1,3-enynes with Vinylaziridines, -epoxides, and -cyclopropanes
Drew, Melanie A.,Tague, Andrew J.,Richardson, Christopher,Pyne, Stephen G.,Hyland, Christopher J. T.
supporting information, p. 4635 - 4639 (2021/06/28)
A two-step Pd-catalyzed (3 + 2) cycloaddition/HNO2 elimination reaction sequence has been developed to give novel cyclic 1,3-dien-5-yne systems from Pd-stabilized zwitterionic 1,3-dipoles and 2-nitro-1,3-enyne substrates. The process is highly atom-efficient and tolerates the reaction of 2-vinyloxirane, 1-tosyl-2-vinylaziridine, and diethyl 2-vinylcyclopropane-1,1-dicarboxylate derived 1,3-dipoles with a variety of 2-nitro-1,3-enyne substrates. The stereochemistry of the intermediate (3 + 2) cycloadducts was determined by single crystal X-ray analysis. Furthermore, a selective kinetic elimination of the cycloadduct with an antiperiplanar relationship between the NO2 group and the participating hydrogen was demonstrated, allowing for efficient isolation of a single diastereoisomer of the cycloadduct.
Skeletally Tunable Seven-Membered-Ring Fused Pyrroles
Andreou, Dimitrios,Essien, Nsikak B.,Pubill-Ulldemolins, Cristina,Terzidis, Michael A.,Papadopoulos, Athanasios N.,Kostakis, George E.,Lykakis, Ioannis N.
supporting information, p. 6685 - 6690 (2021/09/11)
We describe a copper-mediated method that enables the synthesis of seven-membered-ring fused pyrroles (7-mrFPs). The protocol proceeds via an in situ spiro-intermediate ring expansion and tolerates a library of 7-mrFP derivatives with a broad range of functional groups in a simple step with tangible parameters and substrate adaptations. These rare 7-mrFPs are now accessible on a millimolar scale, and selected examples exhibit high antioxidant activity.
