tert-Butylsulfinamide, (R)-(+)- → (R)-(-)-N-[(4-allyldimethylsilylphenyl)methylene]-tert-butanesulfinamide

Participants

Reaction Steps

To a solution of (R)-(−)-tert-butanesulfinamide (3.7 g, 30 mmol) and 4-allyldimethylsilylbenzaldehyde (2 Scheme 1, 6.2 g, 30 mmol) in dry THF (15 mL) was added titanium(IV) propoxide (17 mL, 60 mmol). The mixture was refluxed for 1 h under a N2 atmosphere. The mixture was cooled immediately upon reaction completion, and poured into a brine (30 mL) with rapid stirring. The resulting white suspension was filtered through a pad of celite, which was then washed with ethyl acetate (100 mL). The filtrate was transferred to a separatory funnel where the organic layer was washed with brine (20 mL). The organic layer was dried (Na2SO4), concentrated. The crude oil was purified by column chromatography (1:5 ethyl acetate/hexanes) to afford a colorless oil (6.3 g, 68%); 1H NMR (300 MHz, CDCl3) δ 0.30 (s, 6 H), 1.26 (s, 9 H), 1.76 (d, J=7.92 Hz, 2 H), 4.83 (s, 1 H), 4.88 (d, J=4.41 Hz, 1 H), 5.74 (ddt, J=15.84, 9.27, 8.28 Hz, 1 H), 7.62 (d, J=7.92 Hz, 2 H), 7.82 (d, J=7.92 Hz, 2 H), 8.59 (s, 1 H); 13C NMR (75 MHz, CDCl3) −3.5 (2C), 22.6 (3C), 23.4, 57.8, 113.9, 128.4 (2C),134.0, 134.2 (2C), 134.4, 144.6, 162.8; HRMS (M+1) calcd for C16H26NOSSi 308.1505, found 308.1415.

Provenance & Evidence