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Intramolecular reaction
About: Intramolecular reaction is a research topic. Over the lifetime, 5015 publications have been published within this topic receiving 138213 citations.
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TL;DR: In this article, an experimental study of the distance dependence of intramolecular, long-distance hole transfer in organic radical cations has been performed, where the aromatic donor and acceptor groups, biphenyl and naphthalene (D and A), were held at fixed distances by five rigid saturated hydrocarbon spacer groups.
Abstract: An experimental study of the distance dependence of intramolecular, long-distance hole transfer in organic radical cations has been performed. The aromatic donor and acceptor groups, biphenyl and naphthalene (D and A), were held at fixed distances by five rigid saturated hydrocarbon spacer groups. The kinetics of the transfer reactions (D{sup +}SA {yields} DSA{sup +}) were monitored by transient absorption of the hole donor, 4-biphenylyl radical cation. Intramolecular hole-transfer rate constants were determined for this process and compared with previous results for electron transfer in radical anions of the identical molecules. A comparison of the hole- and electron-transfer results reveals that the attenuation of the rate constants, and therefore the electronic coupling, as a function of distance is the same for both within the limits of error of the experiment.
144 citations
TL;DR: The intramolecular reaction of donor-acceptor cyclopropanes with various dipoles and dipolar equivalents allows access to a variety of bicyclic adducts with good stereo control as discussed by the authors.
Abstract: The intramolecular reaction of donor-acceptor cyclopropanes with various dipoles and dipolar equivalents allows access to a variety of bicyclic adducts with good stereo control The linkers can often be cleaved to provide stereodefined products
144 citations
TL;DR: This work has succeeded in generating iodinated tungsten vinylidene complexes from 1-iodo-1-alkynes and W(CO)5(thf), and has employed these complexes for two types of synthetically useful reactions, that is, 6pi-electrocyclization for o-(iodoethynyl)styrenes and endo-selective cyclization for omega-iodOacetylenic silyl enol ethers.
Abstract: We have succeeded in generating iodinated tungsten vinylidene complexes from 1-iodo-1-alkynes and W(CO)5(thf), and have employed these complexes for two types of synthetically useful reactions, that is, 6π-electrocyclization for o-(iodoethynyl)styrenes and endo-selective cyclization for ω-iodoacetylenic silyl enol ethers.
143 citations
TL;DR: A homologous series of bis-silicon-bridged stilbenes has been synthesized on the basis of a new intramolecular reductive cyclization of bis(o-silyl)-diphenylacetylenes with excess lithium naphthalenide.
Abstract: A homologous series of bis-silicon-bridged stilbenes has been synthesized on the basis of a new intramolecular reductive cyclization of bis(o-silyl)-diphenylacetylene. Thus, the reaction of bis(o-silyl)-diphenylacetylenes with excess lithium naphthalenide undergoes the two-electron reduction at the acetylene moiety to produce a dianion intermediate, which further undergoes a double cyclization in a 5-exo mode to produce the bis-silicon-bridged stilbenes. This methodology can also be applied to the synthesis of tetrakis-silicon-bridged bis(styryl)benzenes. The silicon-bridged pi-conjugated systems thus prepared show intense fluorescence in the visible region. Comparison of a bis-silicon-bridged stilbene with its carbon analogue demonstrates the substantial effects of the silicon-bridges on the electronic structures and thus on the fluorescence properties.
142 citations
TL;DR: A conceptually novel approach for asymmetric intramolecular hydroamination, hydroalkoxylation and hydrocarbonation of alkynes using chiral palladium catalysts are described and the origins of enantioselectivities in the hydroamination reaction are discussed based on DFT computations.
Abstract: A conceptually novel approach for asymmetric intramolecular hydroamination, hydroalkoxylation and hydrocarbonation of alkynes using chiral palladium catalysts are described. The reactions of the aminoalkynes 5, alkynols 7, and alkynylmethines 9 in the presence of Pd2(dba)3·CHCl3/PhCOOH/renorphos 4 in benzene (or benzene−hexane) at 100 °C gave the corresponding cyclization products (nitrogen heterocycles 6, oxygen heterocycles 8, and carbocycles 10) in good yields with good enantioselectivities. The origins of enantioselectivities in the hydroamination reaction are discussed based on DFT computations.
141 citations