51703-63-0Relevant articles and documents
Acceleration of the reduction of aldehydes and ketones using Mn(dpm)3 catalyst and phenylsilane in the presence of dioxygen
Magnus, Philip,Fielding, Mark R
, p. 6633 - 6636 (2007/10/03)
Saturated ketones and aldehydes are reduced to alcohols by phenylsilane and Mn(dpm)3(cat) in the presence of dioxygen.
Ion-molecule complexes in 1,2 alkyl shifts
Gappa, Andrea,Herpers, Ekkehard,Herrmann, Roland,Hülsewede, Volker,Kappert, Wilhelm,Klar, Matthias,Kirmse, Wolfgang
, p. 12096 - 12106 (2007/10/03)
The internal return of neutral leaving groups was studied in rearrangements of polycyclic systems (2-norpinyl → 2-norbornyl, endo- → exo-tricyclo[5.2.1.02.6]dec-8-yl, bicyclo[3.2.0]hept-2-yl → 7-norbornyl, and 4-protoadamantyl → 2-adamantyl). Acid catalysis was applied to 18O-labeled alcohols in aqueous organic solvents, to alcohols in methanol, and to ethers R-O-R′ in alcohols R″-OH. The leaving group was found to attack the migration origin in competition with solvent molecules. Return:exchange ratios were obtained from product distributions, either directly or by kinetic simulation (in cases of partial exchange prior to rearrangement). If departure and return of the leaving group occur on the same side of the carbon framework, return:exchange ratios ranging from 1 to 11.5 were observed. Less internal return was found for bridged than for open carbocations. Migration of the departing molecule to the opposite face (exo ? endo) or to a β carbon is a minor process (return:exchange ～ 0.1), in accordance with previous reports on inverting displacements and allylic 1,3 shifts. These data are rationalized in terms of short-lived ion-molecule (ion-dipole) complexes whose collapse competes with ligand exchange.
Trapping of the 6,6-Dimethylbicyclohept-2-yl Free Radical by SH2 Reaction upon Peracid
Fossey, Jacques,Lefort, Daniel,Sorba, Janine
, p. 3584 - 3587 (2007/10/02)
The free radical 6,6-dimethylbicyclohept-2-yl (7) has been obtained by decarboxylation of cis- or trans-6,6-dimethylbicycloheptane-2-peroxycarboxylic acids (6a and 6b). 7 trapped by reaction with the initial peracid gave a stereochemical mixture of α- and β-nopinol (8a and 8b).The ratio 8b/8a is around 12, independent of the initial peracid 6a or 6b and its initial concentrations.This value is mainly due to the steric effect of one of the methyl groups branched on C7 in 7.The structure of 7 is discussed.By a competitive reaction 7 undergoes ring opening to afford 2-(3-cyclohexenyl)-2-propyl free radical (9) which by reaction upon peracid leads to 2-(3-cyclohexenyl)-2-propanol (10). 7 was successfully trapped because its reaction with peracid is rapid enough.The ratio of the two alcohols 8/10 leads to an estimation of 1*106 M-1 s-1 for the rate constant of the reaction of 7 with peracids
