Abstract A straightforward and convenient method for the one‐pot synthesis of thioamides has been developed by using a three‐component reaction involving readily available benzyl chlorides, amines, and elemental sulfur. A variety of thioamides were synthesized in satisfactory yields (up to 88 %). This approach was scalable and tolerated a wide range of functional groups on the aromatic ring. It was also compatible with some heterocycle substrates, provided efficient and practical access to thioamides. No transition metals or external oxidants were required in the reaction. A plausible mechanism is also proposed on the basis of some control experiments.
Chemical compositions of an unknown paint were characterized by Fourier transform infrared spectrometer(FT-IR) and GC-MS.The IR spectrum was analyzed on-line retriceval and determined the chemical composition of the coatings,the data was tested and verified with GC-MS data,the main components of the coatings were confirmed finally.
An enzyme-mimetic model follows squalene hopene cyclase is success in catalysis of ROP of δ-valerolactone in solution at room temperature by a carboxylic “strong” acid.
Abstract A series of alkyl‐subsituted dienyltriphenylarsonium ylides were synthesized and used as monomers in borane‐initiated polymerization to obtain practically pure C5‐polymers (main‐chain grows by five carbon atoms at a time). The impact of triethylborane (Et 3 B), tributylborane (Bu 3 B), tri‐ sec ‐butylborane ( s ‐Bu 3 B), and triphenylborane (Ph 3 B) initiators on C5 polymerization was studied. Based on NMR and SEC results, we have shown that all synthesized polymers have C5 units with a unique unsaturated backbone where two conjugated double bonds are separated by one methylene. The synthesized C5‐polymers possess predictable molecular weights and narrow molecular weight distributions ( M n,NMR =2.8 −11.9 kg mol −1 , Ð =1.04–1.24). It has been found that increasing the steric hindrance of both the monomer and the initiator can facilitate the formation of more C5 repeating units, thus driving the polymerization to almost pure C5‐polymer (up to 95.8 %). The polymerization mechanism was studied by 11 B NMR and confirmed by DFT calculations. The synthesized C5‐polymers are amorphous with tunable glass‐transition temperatures by adjusting the substituents of monomers, ranging from +30.1 °C to −38.4 °C. Furthermore, they possess blue photoluminescence that changes to yellow illuminating the polymers for 5 days with UV radiation of 365 nm (IIE, isomerization induced emission).
An unprecedented route for the preparation of fused tetracyclic N-heterocycles is presented through the palladium-catalyzed cyclization of isocyanides with alkyne-tethered aryl iodides. In this transformation, a novel amino-to-alkyl 1,5-palladium migration/intramolecular C(sp3)-C(sp2) coupling sequence was observed first. More importantly, isocyanide exhibited three roles, serving simultaneously as a C1 synthon, a C1N1 synthon, and the donor of C(sp3) for C(sp3)-C(sp2) coupling, and the reaction was the sole successful example that achieved C(sp3)-H activation of isocyanide.
Morphological development of phase-separated domains was observed in polymerizing n-butyl methacrylate system by using a phase contrast microscope. Three distinct structures, namely, droplets, network, and spongelike domains, formed in the order of increasing initial monomer weight fraction w. The network and spongelike structure closely resembled those observed in the viscoelastic phase separation of a nonreacting system, but droplets formed at lower w showed rather characteristics of the normal phase separation: The droplets coalesced easily by collisions and had a wide size distribution. In addition to the crossover behavior from the viscoelastic to the normal phase separation with decreasing w, it was also observed that phase separation dynamics at a fixed w changed from the normal to the viscoelastic with a lapse of phase separation time. Comparison with the 4-cholostyrene/poly(dimethylsiloxane-co-diphenylsiloxane) (PDMSDPS) system, in which noncoalescing droplets with narrow size distribution (the moving droplets) formed over a wide range of w, was made, and the origins of the difference in the morphological development between these systems were discussed. It was speculated that the segregation strength between PDMSDPS and polymerization product was a primary cause of the difference in morphological structures.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMercuration of Schiff bases of substituted benzylideneanilinesKuiling Ding, Yangjie Wu, Hongwen Hu, Lianfang Shen, and Xin WangCite this: Organometallics 1992, 11, 11, 3849–3856Publication Date (Print):November 1, 1992Publication History Published online1 May 2002Published inissue 1 November 1992https://pubs.acs.org/doi/10.1021/om00059a058https://doi.org/10.1021/om00059a058research-articleACS PublicationsRequest reuse permissionsArticle Views386Altmetric-Citations23LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
Sechs Reaktionen ohne die Isolierung von Zwischenstufen ermöglichen die stereoselektive Synthese von di- und trisubstituierten Vinyltriflonen und Heteroaryltriflonen aus gem-Dibromvinylsubstraten. In der Zuschrift auf S. 12860 ff. erkunden N. Shibata et al. die Schlüsselschritte dieses Verfahrens. Das Titelbild zeigt ein Gemälde im japanischen Stil von Mami Shibata (Studentin an der Tama-Kunsthochschule), das den Namen “Kaze” (deutsch: Brise) hat. Die sechs Reaktionen verlaufen sehr sanft, so wie sich Vögel in einer Brise wiegen. Sechs Reaktionen ohne die Isolierung von Zwischenstufen ermöglichen die stereoselektive Synthese von di- und trisubstituierten Vinyltriflonen und Heteroaryltriflonen aus gem-Dibromvinylsubstraten. In der Zuschrift auf S. 12860 ff. erkunden N. Shibata et al. die Schlüsselschritte dieses Verfahrens. Das Titelbild zeigt ein Gemälde im japanischen Stil von Mami Shibata (Studentin an der Tama-Kunsthochschule), das den Namen “Kaze” (deutsch: Brise) hat. Die sechs Reaktionen verlaufen sehr sanft, so wie sich Vögel in einer Brise wiegen. Molekulare Elektronik In ihrer Zuschrift auf S. 12762 ff. berichten K. Müllen, L. F. Chi et al. über dendritische organische Halbleiter-Mikrostreifen aus einheitlichen und definierten Mono- bis Hexaschichten.1 Cofaktor-Biosynthese S. Shima et al. klären in ihrer Zuschrift auf S. 12787 ff. einen Reaktionsschritt der Biosynthese des [Fe]-Hydrogenase-Cofaktors mithilfe von struktureller Genomik, Modellreaktionen und Röntgenkristallographie auf.1 Subporphyrine In ihrer Zuschrift auf S. 12864 ff. beschreiben A. Osuka, D. Kim et al. die S2-Fluoreszenz und die photophysikalischen Eigenschaften der höherliegenden angeregten Zustände von Subporphyrinen.1
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