2565-82-4Relevant articles and documents
Organometallic derivatives of natural products: Dicobalt hexacarbonyl complexes of geranyl-alkynes
Moore, Angela,Ostermann, Johannes,Ortin, Yannick,McGlinchey, Michael J.
, p. 7881 - 7888 (2016)
Treatment of methyl geranyl ether with diiron nonacarbonyl leads to hydrogen migration to form previously unknown E and Z 1-methoxy-3,7-dimethyl-1,6-octadiene in low yield. Sodium propargyl alkoxide and geranyl bromide yield propargyl geranyl ether, 13; subsequent reaction with dicobalt octacarbonyl and then bis(diphenylphosphino)methane furnishes the corresponding alkyne-Co2(CO)4(dppm) tetrahedral cluster, 16. Reaction of geranylacetone with phenylethynyl-lithium, and then with Co2(CO)8, forms (1-phenyl-3,7,11-trimethyldodeca-6,10-dien-1-yn-3-ol)Co2(CO)6, 19. The carbynyltricobaltnonacarbonyl clusters RC(O)CCo3(CO)9, where R = geranyl, 23, or farnesyl, 25, are preparable in very good yield either by reaction of the appropriate alcohol with trichloroacetyl chloride and then Co2(CO)8, or by reaction with the metal-stabilized acylium ion [Co3(CO)9CCO]+, 24. Potential use of these (η2-alkyne)dicobalt complexes in Pauson-Khand or Nicholas cyclizations is discussed.
Bis(phosphine)cobalt dialkyl complexes for directed catalytic alkene hydrogenation
Friedfeld, Max R.,Margulieux, Grant W.,Schaefer, Brian A.,Chirik, Paul J.
supporting information, p. 13178 - 13181 (2015/03/30)
Planar, low-spin cobalt(II) dialkyl complexes bearing bidentate phosphine ligands, (P - P)Co-(CH2SiMe3)2, are active for the hydrogenation of geminal and 1,2-disubstituted alkenes. Hydrogenation of more hindered internal and endocyclic trisubstituted alkenes was achieved through hydroxyl group activation, an approach that also enables directed hydrogenations to yield contrasteric isomers of cyclic alkanes.
Allylic and allenic halide synthesis via NbCl5- and NbBr 5-mediated alkoxide rearrangements
Ravikumar,Yao, Lihua,Fleming, Fraser F.
supporting information; experimental part, p. 7294 - 7299 (2010/01/16)
(Chemical Equation Presented) Addition of NbCl5 or NbBr 5 to a series of magnesium, lithium, or potassium allylic or propargylic alkoxides directly provides allylic or allenic halides. Halogenation formally occurs through a metallahalo-[3,3] rearrangement, although concerted, ionic, and direct displacement mechanisms appear to operate competitively. Transposition of the olefin is equally effective for allylic alkoxides prepared by nucleophilic addition, deprotonation, or reduction. Experimentally, the niobium pentahalide halogenations are rapid, afford essentially pure (E)-allylic or -allenic halides after extraction, and are applicable to a range of aliphatic and aromatic alcohols, aldehydes, and ketones. 2009 American Chemical Society.