Concise Asymmetric Synthesis of β-Trifluoromethylated α,β-Diamino Esters through Addition Reactions of Glycine Esters to CF3-Sulfinylimine

Catalytic stereoselective Mannich-type reactions for construction of fluorinated compounds

For its unique role in developing and designing new bioactive materials and healthcare products, fluoro-organic compounds have attracted remarkable interest. Along with ever-increasing demand for a wider availability of fluorine-containing structural units, a large diversity of methods has been introduced to incorporate fluorine atoms specially in a stereoselective fashion. Among them, catalytic Mannich reaction can proceed with a broad variety of reactants and open clear paths for the synthesis of versatile amine synthons in the synthesis of natural product and pharmaceutical molecules. This review provides an overview of the employment of catalytic asymmetric Mannich reactions in the synthesis of fluorine-containing amine compounds and highlights the conceivable distinct mechanisms.

Chiral N-tert-Butylsulfinyl Imines: New Discoveries

In this account the reactions of chiral N-tert-butylsulfinyl imines with organometallic reagents such as organoalkaline (lithium, sodium, potassium and cesium derivatives), organomagnesium, organozinc, organoboron, organoaluminium, organoindium and organosilicon compounds is comprehensively described. The reactivity in all cases is derived to synthetic applications in order to prepare interesting organic nitrogenated molecules, especially in the field of alkaloid compounds.

Detrifluoroacetylative in Situ Generation of Free 3-Fluoroindolin-2-one-Derived Tertiary Enolates: Design, Synthesis, and Assessment of Reactivity toward Asymmetric Mannich Reactions

The discovery of detrifluoroacetylative in situ generation of a new type of fluorinated amide enolates derived from 3-fluoroindolin-2-one and their asymmetric Mannich additions with sulfinylaldimines bearing fluoroalkyl groups is reported, which afforded α-fluoro-β-(fluoroalkyl)-β-aminoindolin-2-ones containing C-F quaternary stereogenic centers with excellent yields and high diastereoselectivities.

Asymmetric synthesis of quaternary α-fluoro-β-keto-amines via detrifluoroacetylative Mannich reactions

Efficient asymmetric detrifluoroacetylative Mannich addition reactions between 2-fluoro-1,3-di-ketones/hydrates and chiral N-sulfinyl-imines via C-C bond cleavage were reported, which afforded C-F quaternary α-fluoro-β-keto-amines with excellent yields and high diastereoselectivity.

Asymmetric synthesis of (3S,1'S)-3-(1-amino-2,2,2-trifluoroethyl)-1-(alkyl)-indolin-2-one derivatives by addition of (S)-N-t-butylsulfinyl-3,3,3-trifluoroacetaldimine to 1-(alkyl)-indolin-2-ones

This paper presents the first study of the addition reactions between amide-derived nucleophiles and chiral CF3-containing N-sulfinyl-imines. We demonstrate that enolates of 1-(alkyl)-indolin-2-ones cleanly react with (S)-N-t-butylsulfinyl-3,3,3-trifluoroacetaldimine affording 3-(1-amino-2,2,2-trifluoroethyl)-1-(alkyl)-indolin-2-ones of (3S,1'S) absolute configuration as the major reaction products with synthetically meaningful diastereoselectivity and chemical yields. The reactions were shown to be of general practical application for preparation of various oxindole derivatives in a diastereomerically pure form.

Synthesis of trifluoromethyl-containing vicinal diamines by asymmetric decarboxylative mannich addition reactions

Herein is reported a study of asymmetric decarboxylative Mannich addition reactions between (Ss)-N-t-butylsulfinyl-3,3,3-trifluoroacetaldimine and Schiff bases derived from various aldehydes and lithium 2,2-diphenylglycinate. These reactions proceed with excellent diastereoselectivities and good chemical yields, providing a practical method for preparation of trifluoromethyl-containing vicinal diamines. The procedures can be conducted under convenient conditions, rendering this approach of high synthetic value.

Asymmetric synthesis of amino-benzothiazol derivatives by additions of 2-lithiated benzothiazoles to (S)-N-t-butylsulfinyl-ketimines

We reported the asymmetric Mannich reactions between lithium-benzothiazoles and (S)-N-tert-butanesulfinylketimines, which gave unknown type of amino-benzothiazol derivatives of high pharmaceutical potential with up to 96% yields and 99 : 1 diastereoselectivities.

Ni-catalyzed asymmetric decarboxylative Mannich reaction for the synthesis of β-trifluoromethyl-β-amino ketones

A Ni-catalyzed asymmetric decarboxylative Mannich reaction between (S_s)-N-t-butylsulfinyl-3,3,3-trifluoro-acetaldimine and β-keto-acids was reported, affording β-trifluoromethyl-β-amino ketones with excellent yields and diastereoselectivities.

Generalized access to fluorinated β-keto amino compounds through asymmetric additions of α,α-difluoroenolates to CF3-sulfinylimine

CF3-containing chiral imines readily react with α,α-difluoroenolates affording a novel type of β-keto-amino compounds featuring the R-CO-CF2-CH(NH2)-CF3 moiety. The reactions feature exceptional generality allowing preparation of various aromatic, hetero-aromatic and aliphatic derivatives in high yields and diastereoselectivity. The products are configurationally stable and can be transformed to more functionalized complex compounds.

One-pot stereoselective synthesis of α,β-differentiated diamino esters via the sequence of aminochlorination, aziridination and intermolecular SN2 reaction

We report here an efficient one-pot method for the synthesis of α,β-differentiated diamino esters directly from cinnamate esters using N,N-dichloro-p-toluenesulfonamide and benzylamine as nitrogen sources. The key transformations include a Cu-catalyzed aminohalogenation and aziridination, followed by an intermolecular SN2 nucleophilic ring opening by benzylamine. The reactions feature a wide scope of substrates and proceed with excellent stereo- and regioselectivity (anti:syn >99:1) .

The synthesis and strecker reaction of 2-chlorotetrafluoroethanesulfinyl ketimines

A series of 2-chlorotetrafluoroethanesulfinyl ketimines were prepared from 2-chlorotetrafluoroethanesulfinamide and ketones in high yields, and their Strecker reactions with TMSCN have been investigated. High yields and excellent diastereoselectivities were achieved in the presence of a catalytic amount of CsF under mild conditions. The six-membered chairlike models were proposed to account for the high stereoselective Strecker reaction.

Highly efficient and generalized asymmetric synthesis of quaternary stereogenic carbon-containing β-amino indanones/indanoles via Mannich-type additions between 1-indanones and N-tert-butanesulfinylketimines

1-Indanone and acetophenone derived enolates undergo Mannich-type reactions with ketimines in up to 98% yields and >99 : 1 diastereoselectivities.