Enantioselective reformatsky reaction induced by chiral β-amino alcohols

Access to optically pure β-hydroxy esters via non-enzymatic kinetic resolution by a planar-chiral DMAP catalyst

The development of new approaches to obtain optically pure β-hydroxy esters is an important area in synthetic organic chemistry since they are precursors of other high value compounds. Herein, the kinetic resolution of racemic β-hydroxy esters using a planar-chiral DMAP derivative catalyst is presented. Following this procedure, a range of aromatic β-hydroxy esters was obtained in excellent selectivities (up to s = 107) and high enantiomeric excess (up to 99% ee). Furthermore, the utility of the present method was demonstrated in the synthesis of (S)-3-hydroxy-N-methyl-3-phenylpropanamide, a key intermediate for bioactive molecules such as fluoxetine, tomoxetine or nisoxetine, in its enantiomerically pure form.

Discovery of orteronel (TAK-700), a naphthylmethylimidazole derivative, as a highly selective 17,20-lyase inhibitor with potential utility in the treatment of prostate cancer

A novel naphthylmethylimidazole derivative 1 and its related compounds were identified as 17,20-lyase inhibitors. Based on the structure-activity relationship around the naphthalene scaffold and the results of a docking study of 1a in the homology model of 17,20-lyase, the 6,7-dihydro-5H-pyrrolo[1,2-c]imidazole derivative (+)-3c was synthesized and identified as a potent and highly selective 17,20-lyase inhibitor. Biological evaluation of (+)-3c at a dose of 1mg/kg in a male monkey model revealed marked reductions in both serum testosterone and dehydroepiandrosterone concentrations. Therefore, (+)-3c (termed orteronel [TAK-700]) was selected as a candidate for clinical evaluation and is currently in phase III clinical trials for the treatment of castration-resistant prostate cancer.

Palladium-Catalyzed Enantioselective Ring Opening of Oxabicyclic Alkenes with Organozinc Halides

Palladium-catalyzed asymmetric ring opening of oxabenzonorbornadienes with readily available organozinc halides under mild conditions in the presence of (S)-Pr(i)-PHOX produces the corresponding 1,2-dihydronaphth-1-ols in good yield and high enantioselectivity. [reaction: see text]

Highly enantioselective reformatsky reaction of ketones: chelation-assisted enantioface discrimination

[reaction: see text] Highly enantioselective Reformatsky reaction of ketones was accomplished using cinchona alkaloids as chiral ligands. Chelation with the sp(2)-nitrogen adjacent to the reactive carbonyl center contributed the enantioface discrimination for the high enantioselectivities.

Remarkable diastereoselectivity in the addition of allylic and unsaturated diorganozinc reagents to beta-(N,N-dialkylamino)-aldehydes

1,3-Anti amino alcohols 5(a)-18(a) are obtained with high diastereoselectivity by use of diorganozinc reagents in additions to amino aldehydes 2a and 2b. The corresponding Grignard reagents exhibit low to modest diastereoselectivity. The highly diastereoselective zinc-based method makes available a wide range of 4,4-disubstituted cyclohexenone derivatives containing contiguous stereocenters.