Subject binaphthyl

When subjected to Ullmann biaryl reactions, 8-bromo-l-oxazolinylnaph-thalene (,S)-27 can be converted to the 8,8 -substituted binaphthyl 28 in high diastereomeric excess (another isomer, the (a/ ,b )-diastcrcomer, is less than 3%).40... 

The keto-enol equilibrium of the 1,3-diketones has been the subject of intensive studies using various physical techniques and theoretical calculations [78-80], Recently, X-ray crystal analysis of acetylacetone (83) was carried out at 110 K, and it was found that it exists as an equilibrium mixture of the two enol forms 83b and 83c [81]. Room-temperature studies show an acetylacetone molecule with the enolic H-atom centrally positioned, which can be attributed to the dynamically averaged structure 83d. Application of a crystal engineering technique showed that a 1 1 inclusion complex of83 can be formed with l,l/-binaphthyl-2,2/-dicarboxylic acid in which the enol form is stabilized by a notably short intramolecular hydrogen bond [82],... 

Diels-Alder reactions have been very successfully subjected to asymmetric catalysis by binaphthyl complexes. Accordingly, the synthesis of tetrahydropyranes 41 and 42 can be realized by reaction of glyoxylic esters 39 with methoxy-dienes 38 (Scheme 8) [20]. Some of these reactions take place with excellent endo-conxro and... 

Rhodium and ruthenium complexes of 2,2 -bis(diphenylphosphino)-l,l -binaphthyl (BINAP) have frequently been used as catalysts for enantioselective hydrogenation of olefins and ketones." "" From consideration of the literature on this subject, it was proposed that the presence of a mono-oxidized BINAP in an organometallic catalyst could have interesting consequences." Accordingly, Rh(BINAP)(CO)Cl was prepared, and upon reaction with O2, (BINAP(0))Rh(CO)Cl was formed. These compounds were authenticated by X-ray crystallography, and IR and NMR spectroscopies. The kinetics of this reaction were monitored by solution (chloroform was the solvent) IR spectroscopy. In the absence of added CO, the oxygenated compound was formed in about 50% yield. BINAP(0)2 and CO2 are also produced. Plots of obs (from loss of reactant) versus [O2] at various temperatures yielded... 

A 2-phosphinoxido-2 -alkanesulfonyl-binaphthyl was subjected to deoxygenation using trichlorosilane and the so-formed intermediate underwent a lithium diisopropylamide-mediated thia-Fries rearrangement to provide the enantiomerically pure 2-phosphino-2 -hydroxy-3 -alkanesulfo-nyl-binaphthyl (Scheme 43). ... 

Phosphorus is a key element in catalysis, and the last two Nobel prizes in molecular chemistry were awarded to Noyori, Sharpless and Knowles (2001) for their work on enantioselective catalysis and to Grubbs, Schrock and Chauvin (2005) for their work on the chemistry of transition metal carbene complexes and their applications in metathesis. In both cases the development of highly efficient, specifically tailored phosphorus based ligands are of paramount importance The book opens with an account of the recent studies on a new family of air-stable chiral primary phosphines based on the binaphthyl backbone and their applications in asymmetric hydrosilylations (Chap. 1). The concept of applying phosphorus ligands to enantioselective catalysis is also the main subject of Chaps. 5 and 10, dealing with P-based planar chiral ferrocenes and chiral phosphorus ligands for enantioselective enyne cycloisomerizations, respectively. 

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