136705-66-3Relevant articles and documents
Oxazaborolidine-catalysed reduction of alk-2-ene-1,4-diones. A convenient access to chiral 1,4-diols
Bach, Jordi,Berenguer, Ramon,Garcia, Jordi,Lopez, Marta,Manzanal, Judith,Vilarrasa, Jaume
, p. 14947 - 14962 (2007/10/03)
An efficient method for the preparation of C2-symmetric, chiral alk-2- ene-1,4-diols (4) has been achieved, based on the borane-mediated reduction of symmetric alk-2-ene-1,4-diones (2) in the presence of oxazaborolidine (R)- 1. In general, the presence of the double bond in 2 has been beneficial (compared with the related saturated 1,4-diketones 3) not only as far as the stereoselectivity in the reduction step is concerned, but also because it allowed us to remove meso-4 by chomatography and/or to improve the stereochemical purity of several resulting mixtures of diols 4 by Sharpless' epoxidation. Enantioenricbed compounds 4 have been readily reduced to saturated diols with negligible loss of optical purity.
New chiral phospholanes; synthesis, characterization, and use in asymmetric hydrogenation reactions
Burk,Feaster,Harlow
, p. 569 - 592 (2007/12/18)
We describe the practical synthesis of enantiomerically pure trans-2,5-disubstituted-1-phenylphospholanes which are then employed in the preparation of a new series of C2-symmetric bis- and C3-symmetric tris(phospholane) ligands. A versatile three-step route to the important chiral 1,4-diol intermediates, used in the phosphine syntheses, is outlined. Rhodium complexes bearing the new phosphine ligands were prepared and shown to act as efficient catalyst precursors for the enantioselective hydrogenation of various unsaturated substrates.
