C-Phosphanylated sulfoximines: synthesis and applications in asymmetric allylic substitution reactions

Starting from cyclic sulfonimidates, a number of C-phosphanylated enantiomerically pure sulfoximines have been prepared either as such or in protected form. Two of them, 5a and epi-5a, have been used as ligands in palladium complex catalyzed allylic substitution reactions delivering the substitution product with up to 95% ee.

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(SS,1S)-N-[1-(Diphenylphosphanylmethyl)-2-methylpropyl]-(S)-methyl-(S)-para-toluene-sulfoximine borane complexC25H33BNOPS[α]D20=+3.7 (c 1.01, CH2Cl2)Source of chirality: (2S,4S)-4-isopropyl-2-para-toluene-4,5-dihydro-[1,2λ6,3]oxathiazole-2-oxideAbsolute configuration: (SS,1S)

(RS,1S)-N-[1-(Diphenylphosphanylmethyl)-2-methylpropyl]-(S)-methyl-(S)-para-toluene-sulfoximine borane complexC25H33BNOPS[α]D20=-72.4 (c 0.45, CH2Cl2)Source of chirality: (2R,4S)-4-isopropyl-2-para-toluene-4,5-dihydro-[1,2λ6,3]oxathiazole-2-oxideAbsolute configuration: (RS,1S)

(SS,1S)-N-[1-(Hydroxymethyl)-2-methylpropyl]-(S)-methyldiphenylphaneoxide-(S)-para-toluene-sulfoximineC25H30BNO3PS[α]D20=+9.1 (c 3.20, CH2Cl2)Source of chirality: (2S,4S)-4-isopropyl-2-para-toluene-4,5-dihydro-[1,2λ6,3]oxathiazole-2-oxideAbsolute configuration: (SS,1S)

(SS,1S)-N-[1-[[(tert-Butyldimethylsilyl)oxy]methyl]-2-methylpropyl]-(S)-2-diphenylphosphanylethyl-(S)-para-toluene-sulfoximine borane complexC32H49BNO2PSSi[α]D20=+25.75 (c 1.2, CH2Cl2)Source of chirality: (2S,4S)-4-isopropyl-2-para-toluene-4,5-dihydro-[1,2λ6,3]oxathiazole-2-oxideAbsolute configuration: (SS,1S)