128364-39-6Relevant articles and documents
Catalytic enantioselective cross-couplings of secondary alkyl electrophiles with secondary alkylmetal nucleophiles: Negishi reactions of racemic benzylic bromides with achiral alkylzinc reagents
Binder, Joerg T.,Cordier, Christopher J.,Fu, Gregory C.
supporting information, p. 17003 - 17006,4 (2012/12/11)
We have developed a nickel-catalyzed method for the asymmetric cross-coupling of secondary electrophiles with secondary nucleophiles, specifically, stereoconvergent Negishi reactions of racemic benzylic bromides with achiral cycloalkylzinc reagents. In contrast to most previous studies of enantioselective Negishi cross-couplings, tridentate pybox ligands are ineffective in this process; however, a new, readily available bidentate isoquinoline-oxazoline ligand furnishes excellent ee's and good yields. The use of acyclic alkylzinc reagents as coupling partners led to the discovery of a highly unusual isomerization that generates a significant quantity of a branched cross-coupling product from an unbranched nucleophile.
NMR study of ?-?* stereoelectronic interactions in 3-substituted benzocycloheptene derivatives
Aubin, Y.,St-Jacques, M.
, p. 543 - 552 (2007/10/02)
Dynamic NMR methods are used to study 3-substituted benzocycloheptene derivatives, useful models for investigating the conformational effect of the stereoelectronic ?-?* orbital interaction.The 11 compounds studied are divided in two subgroups, the first one containing mainly halogenated derivatives (F, Cl, Br, and OCH3) and the second consisting of oxy derivatives (OCH3, OCH2CH3, OCH=CH2, OAc, p-OPh-R, where R = H, OCH3, and NO2).The results for the first series show the presence of two chair conformations (Ca and Ce) characterized by a decreasing Ca population with increasing electronegativity of the substituent.This trend suggests the presence of a dominant ?-?* interaction for Cl and Br stabilizing the Ca form.The larger Ce population observed for F suggests that a strong attractive interaction with the aromatic peri hydrogen is present in this compounds.Finally, in the oxy-substituent series, the populations trend does not correspond to that predicted from the ?-?* orbital interaction, but the individual population perturbations appear to be caused primarily by electrostatic interactions involving the nonsymmetrical polar substituents.
