- Lewis acid catalyzed inverse electron-demand diels-alder reaction of 1,2-diazines
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A systematic approach toward Lewis acid catalyzed inverse electron-demand Diels-Alder (IEDDA) reactions of 1,2-diazines is described. The general concept is first investigated by DFT calculations, supported by spectroscopic data, and finally proven in the experiment.
- Kessler, Simon N.,Wegner, Hermann A.
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- Synthesis and Ring Strain of a Benzoborirene-N-Heterocyclic Carbene Adduct
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The reduction of an N-heterocyclic carbene (1,3-diisopropyl-4,5-dimethylimidazolin-2-ylidene, IiPrMe2) adduct of dichloro(ortho-bromophenyl)borane by tert-butyl lithium at low temperature yields the IiPrMe2 adduct A of parent benzoborirene, a highly strained boron-containing bicyclic compound. A is unstable at room temperature and dimerizes at low temperature to the bis-IiPrMe2 adduct of 9,10-dihydro-9,10-diboraanthracene, characterized by single-crystal X-ray crystallography.
- Hahn, Jennifer,Keck, Constanze,Maichle-M?ssmer, C?cilia,von Grotthuss, Esther,Ruth, Paul Niklas,Paesch, Alexander,Stalke, Dietmar,Bettinger, Holger F.
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supporting information
p. 18634 - 18637
(2018/11/25)
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- Borylation of Arylsilanes, II. - Synthesis and Reactions of Silylated Dihalogenphenylboranes
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Upon treatment with trihaloboranes 4a and 4b the bissilylated benzenes 1, 2, and 3 yield the silylated dihalogenphenylboranes 5a-7b under substitution of one silyl group only.The corresponding difluoroboranes 5c-7c are easily accessible by a new fluorination method under mild reaction conditions by treating the dichloroboranes with lithium fluoride in ether.Upon heating with excess 4 the exchange of the second silyl group occurs, too, yielding the position-isomeric diborylbenzenes 9, 10, and 11.The bromination of the silylated dichlorophenylboranes 5a-7a proceeds with high regioselectivity under desilylation yielding 12, 13, and 14.The dimethoxyboranes 15, 16, and 17, synthesized by methanolysis of the corresponding dichloroboranes, can be coupled with bromobenzene under palladium(0) catalysis to yield the position-isomeric silylated biphenyls 18, 19, and 20.
- Kaufmann, Dieter
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p. 901 - 906
(2007/10/02)
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