824-58-8Relevant academic research and scientific papers
Solvent-free chelation-assisted catalytic C-C bond cleavage of unstrained ketone by rhodium(I) complexes under microwave irradiation
Ahn, Jeong-Ae,Chang, Duck-Ho,Young, Jun Park,Ye, Rim Yon,Loupy, Andre,Jun, Chul-Ho
, p. 55 - 58 (2007/10/03)
A highly efficient C-C bond cleavage of unstrained aliphatic ketones bearing β-hydrogens with olefins was achieved using a chelation-assisted catalytic system consisting of (Ph3P)3RhCl and 2-amino-3-picoline by microwave irradiation under solvent-free conditions. The addition of cyclohexylamine catalyst accelerated the reaction rate dramatically under microwave irradiation compared with the classical heating method.
Double acylation of alkenes with acylchromates promoted by cationic Pd(II) complex
Yamane, Motoki,Ishibashi, Yuichiro,Sakurai, Hidehiro,Narasaka, Koichi
, p. 174 - 175 (2007/10/03)
Double acylation of alkenes such as norbornene and vinyl-silane proceeds by the use of acylchromate complexes and a cationic Pd(II) complex. When two different acylchromates are added successively to a mixture of alkene and the Pd complex, unsymmetrical diketones are obtained almost selectively.
Palladium-catalyzed norbornene-carbon monoxide co-oligomerization initiated by aryl groups and terminated by double bond formation
Dalcanale, E.,An, Z.,Battaglia, L. P.,Catellani, M.,Chiusoli, G. P.
, p. 375 - 388 (2007/10/02)
The use of m-iodophenol as initiator in palladium-catalyzed norbornene-carbon monoxide oligomerization in the presence of potassium acetate unexpectedly leads to termination by double bond formation in spite of the limitations to β-H-anti elimination.The presence of endo products points to preliminary exo-to-endo isomerization through enolization.The X-ray structure of one stereoisomer (Ia) is given.
Hydroboration. 87. Controlled and Sequential Hydroboration of Simple Representative Alkenes with Methylborane in Tetrahydrofuran. An Examination of the Directive Effects in the First and Second Stages of Hydroboration
Srebnik, Morris,Cole, Thomas E.,Brown, Herbert C.
, p. 5051 - 5058 (2007/10/02)
Methylborane (MeBH2), the simplest of the monoalkylboranes, possesses extraordinary hydroborating characteristics in tetrahydrofuran.In this solvent MeBH2 selectively hydroborates all important classes of alkenes, hindered and nonhindered, to yield the methylalkylboranes MeRBH.These dialkylboranes are readily converted into and isolated as their borinic esters, MeRBOR', which in turn can be transformed into methyl ketones, thus providing a simple and highly regio- and stereoselective synthesis of the latter.The addition of a second equivalent of another alkene to the methylalkylborane gives a sequential hydroboration product, MeRARBB.This mixed trialkylborane is readily converted into the corresponding tertiary alcohol via carbonylation-oxidation.The ability to hydroborate an alkene in consecutive stages enables the regioselectivity of the first and second stages of hydroboration to be determined.Thus, the first hydroboration of 1-hexene gives a C-1/C-2 ratio of 98.5:1.5, similar to values obtained with 9-BBN and Sia2BH.The second hydroboration of cis-4-methyl-2-pentene occurs with complete regioselectivity, i.e., 100:0, surpassing the values obtained with the two aforementioned hydroborating agents.MeBH2 is the first example of a sterically nonhindered monoalkylborane capable of stepwise hydroborations of all classes of alkenes.
ROLE OF THE ACETYLACETONYL RADICAL IN THE SENSITIZED PHOTOPRODUCTION OF BIS(ACETONYLACTONATO)COPPER(II)
Cow, Yuan L.,Buono,-Core, Gonzalo E.
, p. 1234 - 1239 (2007/10/02)
Benzophenone-sensitized photoproduction of Cu(acac)2 generated the acetylacetonyl radical (acac.) which could be trapped as acetylacetone by hydrogen as well as by a H-atom-donating agent, or as the corresponding nitroxide with 2-nitroso-2-methylpropane,
Alkylwanderungen bei Sextettumlagerungen
Langhals, Heinz,Range, Guenter,Wistuba, Eckehardt,Ruechardt, Christoph
, p. 3813 - 3830 (2007/10/02)
The migration aptitude of alkyl groups in the Beckmann-, the Criegee-, and the isonitrile-nitrile rearrangements were investigated.The relative rearrangement rates of substituted benzyl groups are an expression of the charge on the migrating carbon at transition state.From the relative rates of migration of exo- and endo-2-norbornyl groups the geometrical changes at the migrating carbon is estimated.Finally, the different influence of α-branching in the migrating group is discussed for these and some other rearrangements.
