The generation and photochemistry of indenone -oxide and fluorenone -oxide in low temperature matrices
作者:Ian R. Dunkin、Gordon A. Bell
DOI:10.1016/s0040-4020(01)96425-7
日期:1985.1
studied, using i.r. spectroscopy. The carbonyl oxides, indenone O-oxide and fluorenone O-oxide, were formed by the reaction of O2 with the corresponding carbenes, and under appropriate conditions could be detected as very photolabile species. Photolysis of indenone O-oxide gave indenone and isocoumarin; similar photolysis of fluorenone O-oxide gave fluorenone and dibenzopyran-6-one.
The Reaction of Diazocyclopentadienyl Compounds with Cyclomanganated Arenes as a Route to Ligand‐Appended Cymantrenes
作者:Jean‐Pierre Djukic、Christophe Michon、Dirk Heiser、Nathalie Kyritsakas‐Gruber、André de Cian、Karl Heinz Dötz、Michel Pfeffer
DOI:10.1002/ejic.200300855
日期:2004.5
The thermolysis of various cyclomanganatedarenes in the presence of 5-diazocyclopentadiene, 7-diazoindene or 9-diazofluorene afforded the corresponding arenes tethered with cymantrenyl, benzocymantrenyl or dibenzocymantrenyl groups in fair to good yields. This reaction implies a multi-facetted mechanism that consists of three steps: the insertion of an alkylidene moiety into a C−Mn bond, a CAr−C bond
The reactions of diazo compounds with lactones. Part 1. Cyclopropanespiro-β-lactones from diketene: synthesis and reactions
作者:Paul V. Murphy、Timothy J. O’Sullivan、Niall W. A. Geraghty
DOI:10.1039/b001393p
日期:——
The cyclopropanespiro-β-lactones 3, 4 and 12 can be prepared by the metal catalysed, or photochemically promoted decomposition reactions of diazocompounds in the presence of diketene. The thermal reactions of these compounds give a variety of products depending on the nature of the spirolactone; these include a furan 9a, 1,4-dicarbonyl compounds 18aâc and 19b, a pyranone 20b, furanones 21a, 21f and 22a and the enol 16. The boron trifluoride promoted reaction of a mixture of 3b and 4b gives a β-ketoacid. Mechanisms are proposed for the formation of these products. The rearrangment of the cyclopropanespiro-β-lactones to furan-2(5H)-ones and furan-2-(3H)-ones 6â8, 21a, 21f, 22a and 24 is shown to be a general reaction that involves metal catalysis. A mechanism based on formation of a metallocycle by a novel insertion of the metal into the CâO bond of the β-lactone ring is proposed for this rearrangement. This accounts for the observed features of the reaction.
Diarylcarbene Complexes of Chromium from Diazo Precursors: Synthesis and Reaction with Electron-Rich Alkynes<sup>1</sup>
作者:Jürgen Pfeiffer、Karl Heinz Dötz
DOI:10.1021/om971086g
日期:1998.9.1
By reaction with pentacarbonyl(η2-cis-cyclooctene)chromium(0) (1) various diaryl diazo compounds have been converted into the corresponding chromium carbenecomplexes 9−15, 18, and 19 which, in certain cases, show extraordinary low-field 13C NMR shifts (>400 ppm) for the carbenecarbonatoms. The carbenecomplexes obtained by this “diazo route” undergo insertion of nucleophilic alkynes such as 1-(
Par photolyse du diazoindene, generation de l'indenylidene dont la reaction avec l'isobutene, les cis- et trans-butenes conduit a desproduitsd'additionet d'insertion comportant des cycles cyclopropane
Par photolyse du diazoindene, generation de l'indenylidene dont la reaction avec l'isobutene, les cis- et trans-butenes pipe a des produits d'addition et d'insertioncomportant des cycle cyclopropane