Supporting information for Titanium isopropoxide as efficient catalyst for… S1 Balan, D.; Adolfsson, H. Titanium isopropoxide as efficient catalyst for the aza- Baylis-Hillman reaction. Selective formation of α- methylene-β-amino acid derivatives Daniela Balan and Hans Adolfsson* Department of Organic Chemistry, Stockholm University, SE-106 91 Stockholm, Sweden hansa@organ.su.se Supporting Information Characterization data for the compounds in Table 2 (melting points are uncorrected). Methyl α-methylene-β-[(p-toluenesulfonyl)amino]-3-(2-furanyl)propionate (3a). Mp 91- 92 °C; 1 H-NMR (400 MHz, CDCl 3 ) δ 2.40 (s, 3H), 3.67 (s, 3H), 5.38 (d, J = 9.3 Hz, 1H), 5.65 (d, J = 9.3 Hz, 1H), 5.84 (s, 1H), 6.05 (dt, J = 3.3 and 0.9 Hz, 1H), 6.21 (dd, J = 3.3 and 1.8 Hz, 1H), 6.23 (s, 1H), 7.21 (dd, J = 1.8 and 0.9 Hz, 1H), 7.24 (d, J = 8.4 Hz, 2H), 7.68 (d, J = 8.4 Hz, 2H); 13 C-NMR (100 MHz, CDCl 3 ) δ 21.73, 52.31, 53.82, 107.64, 110.77, 127.41, 128.59, 129.68, 137.07, 137.76, 142.50, 143.61, 151.41, 165.79; MS (MALDI-TOF) (m/z) 373.943 (MK + ) 357.987 (MNa + ). Anal. Calcd for C 16 H 17 NO 5 S: C, 57.30; H, 5.11; N, 4.18. Found: C, 56.97; H, 5.05; N, 4.07. Methyl α-methylene-β-[(p-toluenesulfonyl)amino]-3-(2-pyridyl)propionate (3b). Work-up as reported for 1 followed by a short column on silica gel to separate the product from the alcohol adduct. Eluent pentane:ethyl acetate 2:1, R f 0.25 Mp 85-86 °C; 1 H-NMR (400 MHz, CDCl 3 ) δ 2.36 (s, 3H), 3.64 (s, 3H), 5.38 (d, J = 8.0 Hz, 1H), 5.87 (s, 1H), 6.25 (s, 1H), 6.51 (d, J = 8.1 Hz, 1H), 7.11 (ddd, J = 7.5, 4.9 and 1.2 Hz, 1H), 7.18 (d, J = 7.8 Hz, 2H), 7.25 (d, J = 8.1 Hz, 1H), 7.54 (dt, J = 7.7 and 1.8 Hz, 1H), 7.66 (d, J = 8.4 Hz, 2H), 8.43 (ddd, J = 4.8, 1.8 and 1.0 Hz, 1H); 13 C-NMR (100 MHz, CDCl 3 ) δ 21.63, 52.12, 58.57, 122.20, 122.73, 127.38, 128.37, 129.56, 136.85, 137.59, 139.05, 143.39, 148.93, 157.09, 166.06; MS (MALDI-TOF) (m/z) 385.059 (MK + ) 369.073 (MNa + ) 347.090 (MH + ). Anal. Calcd for C 17 H 18 N 2 O 4 S: C, 58.94; H, 5.24; N, 8.09. Found: C, 58.76; H, 5.24; N, 7.96. Methyl α-methylene-β-[(p-toluenesulfonyl)amino]-3-(3-chlorophenyl)propionate (3c). Work-up as reported for 1 followed by a short column on silica gel to separate the product