Sulfinyl imine

Ruano has reported substrate-controlled asymmetric ylide aziridination by treatment of enantiopure sulfinyl imines 117 with dimethyloxosulfonium methylide 118 to form terminal aziridines [63], The chiral tert-butylsulfinyl group was shown... 

More recently, Davis and co-workers developed a new method for the asymmetric syntheses of aziridine-2-carboxylates through the use of an aza-Darzens-type reaction between sulfinimines (N-sulfinyl imines) and a-haloenolates [62-66]. The reaction is highly efficient, affording cis- N-sulfmylaziridine-2-carboxylic esters in high yield and diastereoselectivity. This method has been used to prepare a variety of aziridines with diverse ring and nitrogen substituents. As an example, treatment of sulfinimine (Ss)-55 (Scheme 3.18) with the lithium enolate of tert-butyl bromoacetate gave aziridine 56 in 82% isolated yield [66],... 

NSC-135758 428 N-sulfmimines 85 N-sulfinyl imine 80 nucleophilic ring opening 156 nucleophilicity 156... 

Scheme 1.50 Test reaction with P/N-sulfinyl-imine ligand.

Scheme 5.2 Cu-catalysed Diels-Alder reaction with siam ligand and sulfinyl imine...

A highly stereoselective synthesis of the (3-substituted P-amino sulfone 271 involves the addition of a sulfonyl anion, derived from A-PMB sultam 268 upon treatment with NaHMDS, to chiral A-sulfinyl imine (5)-269 <06OL789>. Removal of the A-sulfinyl followed by basic workup affords amine 271. The stereochemical outcome of the adduct 270 was established via proton NMR analysis of the Mosher s amide derived from 271. 

The sulfinyl imine catalyst 63, which has a stereogenic sulfur atom, hydrogenated substrate 36 in 94% ee however, high catalyst loadings were used [45]. The full results for substrates 36 40 are detailed in Tables 30.7 to 30.11. 

Unsymmetrical vicinal diamines are prepared by reductive cross-coupling between nitrones and jY-/-butylsulfmyl imines with Sml2. The coupling proceeds in a high diastereoselective manner. Thus, optically pure unsymmetrical vicinal diamines are produced by using enantiomerically pure sulfinyl imines (Equation (74)). ... 

Addition of organocuprates to IV-sulfinyl imines R2CH=CH-C(R1)=NS(0)-(f-Bu) proceeds in good yields and with good diastereoselectivities (<96 4).222... 

The reduction of the chiral /3-hydroxy sulfinyl imines with HBcat or LiBHEt3 provided syn- and anti- 1,3-amino alcohols, respectively, with very high diastereomeric ratios (Equations (255) and (256)).1072... 

TABLE 18. Asymmetric Mannich reactions using chiral A-sulfinyl imines... 

From semiamidals, the correspondmg tnfluoromethyl substituted N-acyl mines [25, 28], 1,3-diawbutadienes [27], N-sulfonyl immes [5, 29], N sulfinyl imines [30], and N-phosphotyl mines [31] can be obtained m high yields on reaction with powerful dehydrating reacts like POC -pyndine ortnfluoroacetic anhydnde-pyndme [2,5]... 

Davis, F. A., Liu, H., Zhou, P., Fang, T., Reddy, G. V., Zhang, Y. Aza-Darzens asymmetric synthesis of N-(p-toluenesulfinyl)aziridine 2-carboxylate esters from sulfinimines (N-sulfinyl imines). J. Org. Chem. 1999, 64, 7559-7567. 

Sulfinimines (TV-sulfinyl imines) in asymmetric synthesis of pyrrolidines 04T8003. 

Although N sulfinyl imines can be prepared by several other methods (oxidation of sulfenimines [12] and iminolysis of sulfinates [13]), they are most conveniently synthesized by condensing aldehydes with tert butanesulfinamide in the presence of copper(II) sulfate or magnesium sulfate/pyridinium p toluenesulfonate as a Lewis add catalyst and water scavenger (Scheme 1.4) [14]. When ketones, more sterically hindered aldehydes or even electronically deactivated aldehydes are used, titanium tetraethoxide is the preferred Lewis add and water scavenger. These methods are convenient to synthesize both alkyl and aryl substituted imines. 

Scheme 1.13 Addition of methylmagnesium chloride to N sulfinyl imines.

Scheme 1.14 Allylation, benzylation, and alkenylation of N sulfinyl imines.

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