Asymmetric Synthesis of (αR)-Polyfluoroalkylated Prolinols Based on the Perfluoroalkyl-Induced Highly Stereoselective Reduction of Perfluoroalkyl N-Boc-pyrrolidyl Ketones

cis-Dihydroxylated α-Trifluoromethylated N,O-Acetal from l-Tartaric Acid: Synthesis of Tetrasubstituted Stereocenter via Diastereoselective Pictet-Spengler Cyclization of N-Acyliminium Ions

The synthesis of cyclic, chiral α-trifluoromethylated N,O-acetals having a protected cis-diol moiety has been readily achieved in two steps from a known bis-Weinreb amide derived from l-tartaric acid. The reaction of O-acetyl analogues of these N,O-acetals with triflic acid in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) at 0 °C generated in situ the corresponding electrophilic α-trifluoromethyl N-acyliminium ions that undergo Pictet-Spengler-type cyclizations. After only 10 min of reaction, the original enantiopure aza-tricyclic scaffolds bearing a trifluoromethyl substituent at the bridgehead position were obtained with diastereoselectivities ranging from 75:25 to 97:3.

Enhancement of stereoselectivities in asymmetric synthesis using fluorinated solvents, auxiliaries, and catalysts

In this review, the drastic changes using fluorinated solvents, additives, auxiliaries, and catalysts in catalytic asymmetric transformations are presented.

Asymmetric synthesis of (αS)-polyfluoroalkylated N-Boc-prolinols by the diethyl zinc-induced asymmetric Meerwein–Ponndorf–Verley reduction of perfluoroalkyl N-Boc-pyrrolidyl ketones

Asymmetric synthesis of (αS)-polyfluoroalkylated prolinols by the asymmetric Meerwein–Ponndorf–Verley-type reduction of perfluoroalkyl N-Boc-pyrrolidyl ketones with Et₂Zn has been developed.

Synthesis of β-amino-α-trifluoromethyl alcohols and their applications in organic synthesis

A comprehensive overview on methods applied for syntheses of β-amino-α-trifluoromethyl alcohols, including stereocontrolled variants, is presented. In addition, reported cases of the exploration of β-amino-α-trifluoromethyl alcohols for the preparation of trifluoromethylated peptidomimetics and other biologically active, fluorinated compounds are discussed. Attractive opportunities for their applications as organocatalysts are also presented.