Towards more chemically robust polymer-supported chiral catalysts for the reactions of aldehydes with dialkylzincs
作者:Roger J. Kell、Philip Hodge、Mohammad Nisar、David Watson
DOI:10.1016/s0960-894x(02)00276-7
日期:2002.7
N-Methyl-alpha,alpha-diphenyl-L-prolinol derivatives with para-bromo substituents in one or both of the phenyl rings are easily bound to crosslinked polystyrene beads containingphenylboronicacidresidues using Suzuki reactions. When the products were used as catalysts for the reactions of aldehydes with diethylzinc in toluene at 20 degrees C, the alcohols were produced in chemical yields >90% and
Towards more chemically robust polymer-supported chiral catalysts: α,α–diphenyl-<scp>l</scp>-prolinol based catalysts for the reduction of prochiral ketones with borane
作者:Roger J. Kell、Philip Hodge、Peter Snedden、David Watson
DOI:10.1039/b306294p
日期:——
either one or both of the phenyl rings are easily bound to crosslinkedpolystyrenebeads containing phenylboronic acid residues by Suzuki couplings. By using extended reaction periods boronicacid residues that do not take part in the couplings are simply lost by hydrolysis. The polymer-supported (PS) alpha,alpha-diphenyl-L-prolinols were used to catalyse reductions of several prochiral ketones with