- Synthesis, structure, and reactivity of a gold carbenoid complex that lacks heteroatom stabilization
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Hydride abstraction from the neutral gold cycloheptatrienyl complex [(P)Au(η1-C7H7)] (P=P(tBu) 2(o-biphenyl)) with triphenylcarbenium tetrafluoroborate at -80 C led to the isolation of the cationic gold cycloheptatrienylidene complex [(P)Au(η1-C7H6)]+ BF 4- in 52 yield, which was characterized in solution and by single-crystal X-ray diffraction. This cycloheptatrienylidene complex represents the first example of a gold carbenoid complex that lacks conjugated heteroatom stabilization of the electron-deficient C1 carbon atom. The cycloheptatrienylidene ligand of this complex is reactive; it can be reduced by mild hydride donors, and converted to tropone in the presence of pyridine N-oxide. Hydride abstraction from the neutral gold cycloheptatrienyl complex 1 (P=P(tBu)2 (o-biphenyl)) with Ph3C+ BF 4- formed the cationic gold cycloheptatrienylidene complex 2, which was characterized by single-crystal X-ray diffraction. The cycloheptatrienylidene ligand of 2 is reactive; it can be reduced by mild hydride donors, and converted into tropone in the presence of pyridine N-oxide.
- Harris, Robert J.,Widenhoefer, Ross A.
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supporting information
p. 9369 - 9371,3
(2015/02/05)
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- The Thermal Addition Reactions of Cycloheptatriene with Aromatic p-Quinones
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Thermal addition reactions of cycloheptatriene with several aromatic p-quinones gave the Diels-Alder adducts as minor products; the most characteristic feature was the formation of the vic-ditropylation products.The mechanism of their formation was clarified to be a sequential ene-reaction and dehydrogenation by means of chemical conversion from the isolated intermediates.Several new other additions, e.g., successive Diels-Alder reactions, were also noted.
- Mori, Akira,Mametsuka, Hiroaki,Takeshita, Hitoshi
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p. 2072 - 2077
(2007/10/02)
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- A PHOTO-INDUCED REACTION BY VISIBLE LIGHT VIA A CHARGE TRANSFER COMPLEX
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The reduction of tropylium cation (Tr+) with concomitant oxidation of O,O'-dialkyldithiophosphate anions (dtp-) have been achived by visible irradiation of their acetonitrile solution in presence of a bipyridium dication; the later via its charge transfer complex with dtp- acts as a light-harvest and as an electron relay.
- Deronzier, Alain
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p. 2867 - 2868
(2007/10/02)
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- Synthesis and Properties of the Tristyrylmethyl Anion
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The title anion (3) having a C3v symmetric structure was generated from newly synthesized tristyrylmethane (4) and was characterized by means of 1H and 13C NMR spectroscopy.The pKa value of 4 was determined as 20.1 in DMSO-EtOH (9:1), indicatin
- Komatsu, Koichi,Shirai, Shuzo,Tomioka, Isao,Okamoto, Kunio
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p. 1377 - 1380
(2007/10/02)
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- Photoadditions of Anthracenes to 2,4-Hexadiene and 1,3,5-Cycloheptatriene
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Electronically excited 9-anthracenecarbonitrile (1*), in contrast to theoretical predictions, is trapped by 2,4-hexadiene to give the -adduct 3 with a trans-double bond, which forms the -adduct 4 above 0 deg C via suprafacial 1,3-shift.Also 1,3,5-cycloheptatriene (6) quenches 1* with the result of a thermolabile -adduct 7 (-> 8).In addition to 8, further adducts (9, 10, 11, 12) are formed via isomeric diradicals.Anthracene (19*) and 6 generate the -, -, -, substitutive, and peripheral adducts 20, 21, 22, 23, and 24. 9-Phenylanthracene (25*) and 6 form the corresponding, partly isomeric, adducts (26; 29; 27, 28; 30, 31; 32).The reactions are interpreted in terms of diradical mechanism.Numerous literature reports, which havealready been classified theoretically, are amended or corrected, the reasons for erroneous theoretical predictions are discussed.The diversity of products can be understood in detail by empirical extrapolations on the basis of the experimentally secured cyclovinylogy principle.
- Kaupp, Gerd,Grueter, Heinz-Willi,Teufel, Eberhard
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p. 630 - 644
(2007/10/02)
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