作者:Z. A. Bredikhina、V. G. Novikova、N. M. Azancheev、A. A. Bredikhin
DOI:10.1023/a:1020815410142
日期:——
The regioisomeric composition of the adducts of unsymmetrical oxiranes with achiral and chiral phosphorochloridites was studied. Factors allowing enantiomeric assessment of chiral oxiranes with the aid of chiral derivatizing organophosphorus reagents were revealed.
New carbohydrate bisphosphites as chiral ligands
作者:Renat Kadyrov、Detlef Heller、Rüdiger Selke
DOI:10.1016/s0957-4166(97)00622-8
日期:1998.1
The synthesis of the 2,3-bisphosphite derivatives of phenyl 4,6-O-benzylidene-beta-D-glucopyranoside leads to new chelating ligands. Their rhodium(I) and platinum(II) complexes have been tested as catalysts for the asymmetric hydroformylation of vinyl acetate, allyl acetate and p-methoxystyrene. Good regioselectivity (>90% branched product), but an enantioselectivity of only less than or equal to 36% ee were found under mild reaction conditions (25-40 degrees C, 40-70 bar syngas). (C) 1998 Elsevier Science Ltd. All rights reserved.
The use of (4r,5r)-dicarboalkoxy 2-chloro 1,3,2-dioxaphospholanes as new chiral derivatizing agents for the determination of enantiomeric purity of alcohols by 31P NMR.
The title compounds are prepared from a dialkyl tartrate and PCl3. Their use as chiral derivatizing agents for the determination of enantiomeric excess of primary, secondary and tertiary alcohols by P-31 NMR is described.