Asymmetric Synthesis of 1-(9-Anthracenyl)ethylamine and Its Trifluoro­methyl Analogue via Nucleophilic Addition to an N-(tert-Butylsulfinyl)imine

Abstract

A s y m m e t r i c S y n t h e s i s o f C h i r a l A m i n e s w i t h a 9 -A n t h r a c e n y l G r o u p Abstract: Asymmetric synthesis of the 9-anthracenyl analogues of 1-phenylethylamine and 2,2,2-trifluoro-1-phenylethylamine was achieved via nucleophilic addition to the corresponding N-(tert-butylsulfinyl)imine.The synthesis of chiral amines is an important endeavor due to the many uses of chiral amines in medicinal chemistry. In asymmetric synthesis such amines are also a primary target because of their uses as ligands and organocatalysts. In this regard, we sought to obtain chiral amines 1 and 2 (Figure 1) in order to incorporate them into (thio)ureas for two purposes: as organocatalysts 1 and for the chiral recognition of carboxylates. 2 Amine 1 has been used previously as a chiral solvating agent 3 and in asymmetric synthesis 4 as a higher analogue of 1-phenylethylamine. 5

Trifluoromethyltrimethylsilane: Nucleophilic Trifluoromethylation and Beyond

“…In the research of the trifluoromethylation of N -tosyl imines, Bernardi and co-workers described a single example of organocatalytic asymmetric trifluoromethylation of imine equivalent 149 using phase-transfer catalysis with phenoxides in the presence of cinchona-derived quaternary ammonium chloride 150 (Scheme ). , In a more recent report, Shibata and co-worker described an asymmetric aerobic epoxidation of β-trifluoromethyl-β,β-disubstituted enones by using catalyst 139 to give enantiomerically enriched trifluoromethylated epoxides with a tetrasubstituted carbon centers …”

“…A trifluoromethyl group can exert steric, electrostatic, and stereoelectronic effects on a reaction site, thereby affects its reactivity. The size of a trifluoromethyl group is close to an isopropyl group and steric parameters and electrostatic effects arising from the presence of fluorine atoms cause fluorine-containing compounds likely to be poor hydrogen-bond acceptors. − While catalytic enantioselective trifluoromethylation of carbonyl electrophiles and imines with 1 has gained recent success, the current chiral catalyst, mainly derived from cinchona bark has significant limitations in substrate scope. Therefore, combined with mechanistic studies, the creation of new catalysts for enantioselective trifluoromethylation is needed …”

Asymmetric Organocatalytic [2,3]‐Wittig Rearrangement of Cyclohexanone Derivatives

“…Catalysts I, III, V, VI, VII, IX, XI and XII were prepared according to literature procedures, and the analytical data matched with that of the literature. [21][22][23][24][25][26][27][28] General Procedure for the Synthesis of 2-Cinnamyloxycyclohexanones 3 a-j. To a solution of cinnamyl alcohol derivative (1.00 eq), zinc triflate (0.40 eq), diisopropylethylamine (2.00 eq) and pyrrolidine (1.00 eq) a mixture of 2-bromocyclohexanone (1.50 eq) in toluene (1 M) was added and the reaction was stirred overnight at room temperature.…”

“…Chiral catalysts II , IV , VIII , and X were commercially available from Aldrich, Acros Organics or Fluorochem. Catalysts I , III , V , VI , VII , IX , XI and XII were prepared according to literature procedures, and the analytical data matched with that of the literature [21–28] …”