118353-44-9

Upstream product

• 538-86-3 benzyl methyl ether 
• 100-52-7 benzaldehyde 
• 5928-67-6 (S)-(+)-benzoin 
• 579-43-1 (1S,2R)-1,2-diphenylethane-1,2-diol 
• 74-88-4 methyl iodide 
• 451-40-1 phenyl benzyl ketone 
• 3524-62-7 benzoin monomethyl ether 
• 86544-37-8 (S)-α-methoxyphenylacetaldehyde 
• 591-51-5 phenyllithium 
• 82572-27-8 (+)-(S)-methoxy-1,2-diphenylethanone 
• 118298-90-1 Trifluoro-acetic acid (S)-2-oxo-1,2-diphenyl-ethyl ester 
• 66051-01-2 (S)-2-methoxy-2-phenylethanol 
• 26164-26-1 (S)-2-methoxy-2-phenylacetic acid 

Relevant academic research and scientific papers

Tandem Acid/Pd-Catalyzed Reductive Rearrangement of Glycol Derivatives

Herein, we describe the acid/Pd-tandem-catalyzed transformation of glycol derivatives into terminal formic esters. Mechanistic investigations show that the substrate undergoes rearrangement to an aldehyde under [1,2] hydrogen migration and cleavage of an oxygen-based leaving group. The leaving group is trapped as its formic ester, and the aldehyde is reduced and subsequently esterified to a formate. Whereas the rearrangement to the aldehyde is catalyzed by sulfonic acids, the reduction step requires a unique catalyst system comprising a PdII or Pd0 precursor in loadings as low as 0.75 mol % and α,α′-bis(di-tert-butylphosphino)-o-xylene as ligand. The reduction step makes use of formic acid as an easy-to-handle transfer reductant. The substrate scope of the transformation encompasses both aromatic and aliphatic substrates and a variety of leaving groups.

Asymmetric hydrogenation of aromatic ketones catalyzed by the TolBINAP/DMAPEN-ruthenium(II) complex: A significant effect of N-substituents of chiral 1,2-diamine ligands on enantioselectivity

(Chemical Equation Presented) Asymmetric hydrogenation of acetophenone in the presence of Ru(II) catalysts coordinated by TolBINAP and a series of chiral 1,2-diamines was studied. The sense and degree of enantioselectivity were highly dependent on the N-substituents of the diamine ligands. The N-substituent effect was discussed in detail. Among these catalysts, the (S)-TolBINAP/(R)- DMAPEN-Ru(II) complex showed the highest enantioselectivity. The mode of enantioface selection was interpreted by using transition state models based on the X-ray structure of the catalyst precursor. The chiral catalyst effected the hydrogenation of alkyl aryl ketones and arylglyoxal dialkyl acetals to afford the chiral alcohol in >99% ee in the best cases. Hydrogenation of racemic benzoin methyl ether with the chiral catalyst through dynamic kinetic resolution gave the anti-alcohol (syn:anti = 3:97) in 98% ee, while the reaction of α-amidopropiophenones resulted in the syn-alcohols (symanti = 96:4 to >99:1) in >98% ee.

Hydrogenation of α-Keto Ethers: Dynamic Kinetic Resolution with a Heterogeneous Modified Catalyst and a Heterogeneous Base

The first successful example of the asymmetric hydrogenation of substituted α-keto ethers with Cinchona-modified Pt/Al2O3 is reported. In the absence of an additional base, kinetic resolution of the racemic starting material was observed with high diastereoselectivity and ee's up to 98% at conversions of a strong reaction acceleration but racemic product. Immobilization of OH- on solid ion exchangers resulted in the desired dynamic kinetic resolution, and ee's of >80% were obtained at >95% conversion. These effects are rationalized on the basis of a simple kinetic and structural model.

Enantioselective reactions of α-methoxybenzyllithium generated by t-BuLi/chiral bis(oxazoline) complex with aldehydes

The title reaction is shown to afford the corresponding 1,2-diol monomethyl ethers in moderate-to-high levels of % ee (up to 98%) and % de (up to 90% anti), depending markedly on the aldehyde reactivity. The origin of the enantioselectivity is discussed i

A practical stereoselective synthesis of chiral hydrobenzoins via asymmetric transfer hydrogenation of benzils

(matrix presented) Asymmetric reduction of benzil with RuCl[(S,S)-Tsdpen)(η6-p-cymene) in a mixture of formic acid and triethylamine proceeds with a substrate/ catalyst molar ratio of 1000-2000 to give (R,R)-hydrobenzoin quantitatively with high diastereomeric (97% de) and enantiomeric purities (>99% ee), in which the benzoin intermediate with a chirally labile stereogenic center is converted to one major stereoisomer, (R,R)-product, via dynamic kinetic resolution.