76499-96-2Relevant academic research and scientific papers
Synthesis of new derivatives of copper complexes of Josiphos family ligands for applications in asymmetric catalysis
Oost,Rong,Minnaard,Harutyunyan
, p. 1997 - 2005 (2014/06/24)
A series of new copper complexes containing chiral ferrocenyl diphosphine ligands of the Josiphos family have been prepared. These complexes have been studied in the catalytic asymmetric 1,2-addition of Grignard reagents to enones and aromatic ketones. Variation of the electronic and steric properties of the ligand resulted in a positive effect in the regio- and enantioselectivity of Grignard reagents to α-H-substituted enones using the ligand in which tert-butyl substituents were introduced in the diarylphosphine moiety. The copper complexes were also successfully applied in the catalytic asymmetric conjugate addition of Grignard reagents to enoates. No increase of enantioselectivity was observed in the catalytic asymmetric addition of linear Grignard reagents, compared to that of the commercially available ligand rev-Josiphos. The Royal Society of Chemistry 2014.
Acetolysis of 2-Aryl-1-methylpropyl Systems: Mechanism of the Formation of the Retained Product without Neighbouring Group Participation
Kinoshita, Tomomi,Takemoto, Masaki,Shibayama, Koichi,Takeuchi, Ken'ichi
, p. 2153 - 2174 (2007/10/02)
threo-2--1-(13C)methylpropyl p-bromobenzenesulphonate (threo-(13C)1-OBs) has been solvolyzed in acetic acid to give rise to the retained threo-1-OAc which contains a small amount of threo-(13C)1-OAc accompanying no 13C-scrambling.At 75percent conversion, the isomerized erythro-1-OBs has been obtained along with the unchanged threo-1-OBs.Also, the erythro-1-OTs has been found at 50percent conversion in the presence of NaOTs.These stereochemical results indicate strongly that the acetate with the retained configuration accompanying no 13C-scrambling is formed via isomerization of the substrate by inversive anion exchange and a successive ks pathway with configurational inversion.Such a retained product was not detected in the acetolysis of threo-1-methyl-2-phenylpropyltoluene-p-sulphonate with no electron withdrawing substituent.
