- Removal of Nerve Agent Simulants from Water Using Light-Responsive Molecular Baskets
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We found that molecular baskets 1-3, with amino acids at their rim, undergo photoinduced decarboxylations to give baskets 4-6 forming a solid precipitate in water. Furthermore, organophosphonates 7-9 (OP), akin in size and shape to G-type nerve agents, form inclusion complexes with baskets 1-3 (K = 6-2243 M-1). Light irradiation (300 nm) of an aqueous solution of 1-3?OP led to the formation of precipitate containing an OP compound thereby amounting to a novel strategy for light-induced sequestration of nerve agents or, perhaps, other targeted compounds. Importantly, the stability of basket OP complexes in addition to functional groups at the basket's rim play a role in the efficiency (up to 98%) by which OPs are removed from water.
- Border, Sarah E.,Pavlovi?, Radoslav Z.,Zhiquan, Lei,Badji?, Jovica D.
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p. 18496 - 18499
(2018/01/11)
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- Design and synthesis of polycyclic sulfones via Diels-Alder reaction and ring-rearrangement metathesis as key steps
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Here, we describe a new and simple synthetic strategy to various polycyclic sulfones via Diels-Alder reaction and ring-rearrangement metathesis (RRM) as the key steps. This approach delivers tri- and tetracyclic sulfones with six (n = 1), seven (n = 2) or eight-membered (n = 3) fused-ring systems containing trans-ring junctions unlike the conventional all cis-ring junctions generally obtained during the RRM sequence. Interestingly the starting materials used are simple and commercially available.
- Kotha, Sambasivarao,Gunta, Rama
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p. 1373 - 1378
(2015/08/24)
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- Oligomeric benzylsulfonium salts: Facile benzylation via high-load ROMP reagents
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(Chemical Equation Presented) The development of high-load, oligomeric benzylsulfonium salts, generated via ring-opening metathesis polymerization, and their utility in facile benzylations of various nucleophiles is reported. These oligomeric sulfonium salts exist as free-flowing powders and are stable at room temperature. After the benzylation event, purification is attained via simple dry load/filtration, followed by solvent removal to deliver products in excellent yield and purity.
- Zhang, Mianji,Flynn, Daniel L.,Hanson, Paul R.
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p. 3194 - 3198
(2008/02/04)
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- A HIGHLY STEREOSELECTIVE SYNTHESIS OF (E)-1- SUBSTITUTED-1,3-DIENES.
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(E)-1-substituted-1,3-dienes are obtained with high selectivity by the thermal extrusion of SO2 from 2-substituted-2,5-dihidrothiophene-1,1-dioxides generated by a retro Diels-Alder reaction.An application to the synthesis of (E)-9,11-dodecadien-1-yl acetate, a sex pheromone of the red-bollworm moth is described.
- Bloch, R.,Abecassis, J.
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p. 3277 - 3280
(2007/10/02)
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- Degenerate Thermal Rearrangement of 1,3-Dimethylenecyclopentane. Evidence for Partially Stereospecific Biradical Formation and Closure in 1,3 Shift
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Parolysis of 1,3-bis(dideuteriomethylene)cyclopentane at 370 deg C resulted in a first-order degenerate rearrangement in which the 1,3- and 3,3-shift products were formed in a 2:1 ratio, respectively, indicating the intermediacy of an effectively orthogonal 2,2'-bis(allylmethane) biradical.Pyrolysis of trans- and cis-4,5-dimethyl-1,3-dimethylenecyclopentane (T and C) gave 1,3- and 3,3-shift products with stereochemistry consistent with predominant conrotatory-bevel ring opening to produce the orthogonal diradical directly.Pyrolysis of optically active T gave the 1,3-shift products with 20.8percent inversion of configuration of the migrating carbon indicative of partial stereospecific closure of the biradical.Comparative pyrolysis of optically active T and its bis(dideuteriomethylene) derivative revealed no secondary kinetic deuterium isotop effect, but an alternation in the extent of racemization of starting material and amounts of 1,3- and 3,3-shift products indicates a product-determining isotope effect.These data provide further evidence for an intermediate.
- Gajewski, Joseph J.,Salazar, Jose Del C.
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p. 4145 - 4154
(2007/10/02)
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