904744-08-7Relevant academic research and scientific papers
A highly efficient synthesis of optically active ferrocenylethylamines via hydride reduction of chiral ferrocenylketimines
Qian, Hengyu,Yan, Shihai,Cui, Xiuling,Pi, Chao,Liu, Cheng,Wu, Yangjie
, p. 992 - 996 (2013/09/02)
Due to using (R)- or (S)-α-methylbenzylamine as a chiral auxiliary, and low-temperature regime for reduction of the intermediate ferrocenyl-mono- or 1,1′-bis-ketimines, the corresponding secondary mono- or 1,1′-bis-amines were prepared with high diastereoselectivity. Removal of the α-methylbenzyl group afforded the optically active primary mono- and bis-ferrocenylethylamines in high yields. The absolute configuration of (R,R)-3a and (S,S)-3b was determined by X-ray single crystal diffraction. We have developed an efficient and highly stereoselective synthesis of the chiral mono- and bis-ferrocenylamines via sodium borohydride reduction, followed by reductive cleavage of the α-methylbenzyl moiety using 5% Pd/C and HCOONH 4. The selectivity was up to 99% de. Copyright
Development of an asymmetric trimethylenemethane cycloaddition reaction: Application in the enantioselective synthesis of highly substituted carbocycles
Trost, Barry M.,Silverman, Steven M.,Stambuli, James P.
, p. 19483 - 19497 (2012/01/06)
A protocol for the enantioselective [3+2] cycloaddition of trimethylenemethane (TMM) with electron-deficient olefins has been developed. The synthesis of novel phosphoramidite ligands was critical in this effort, and the preparation and reactivity of these ligands is detailed. The evolution of the ligand design, commencing with acyclic amine-derived phosphoramidites and leading to cyclic pyrrolidine and azetidine structures, is discussed. The conditions developed to effect an asymmetric TMM reaction using 2-trimethylsilylmethyl allyl acetate were shown to be tolerant of a wide variety of alkene acceptors, providing the desired methylenecyclopentanes with high levels of enantioselectivity. The donor scope was also explored, and substituted systems were tolerated, including one bearing a nitrile moiety. These donors were reactive with unsaturated acylpyrroles, giving the product cyclopentane rings bearing three stereocenters in high enantioselectivity and complete diastereoselectivity.
A convenient, highly stereoselective, metal-free synthesis of chiral amines
Guizzetti, Stefania,Benaglia, Maurizio,Biaggi, Cinzia,Celentano, Giuseppe
supporting information; experimental part, p. 134 - 136 (2010/07/16)
A low cost, efficient, metal-free highly stereoselective reduction of ketimines to chiral amines was developed. Different imines bearing a very cheap and removable chiral auxiliary were reduced simply by trichlorosilane in the presence of N,N-dimethylformamide, often in quantitative yield and complete control of the absolute stereochemistry, to afford highly enantiomerically enriched amines. Georg Thieme Verlag Stuttgart.
Highly stereoselective metal-free catalytic reduction of Lmines: An easy entry to enantiomerically pure amines and natural And Unnatural α-amino esters
Gulzzettl, Stefania,Benagila, Maurizio,Rossi, Sergio
supporting information; scheme or table, p. 2928 - 2931 (2009/12/05)
A highly efficient catalytic stereoselective ketlmlne reduction is described. The combination of an Inexpensive chiral organocatalyst, easily prepared In a single step, and of a very cheap removable chiral auxiliary allowed us to obtain enantlomerlcally pure amino compounds. The methodology allowed synthesis of chiral secondary and primary amines and natural and unnatural amino esters In high yields often with total control of the absolute stereochemistry.
