1: With N-chloro-succinimide; silver nitrate in water; acetonitrile T=0 - 4°C; 2: With sodium tetrahydroborate in water; acetonitrile T=20°C; 3 h;

1: With [35S]-L-(-)-Methionine in water; acetonitrile T=0°C; 0.25 h; 2: With sodium tetrahydroborate; 1,8-diazabicyclo[5.4.0]undec-7-ene in tetrahydrofuran; water T=0°C; 0.25 h;

[3,4-a]phthalazine; osmium(VIII) oxide; dihydrogen peroxide; dihydroquinidine other reagent; Product distribution;

sodium tetrahydroborate in ethanol T=0°C; Yield given;

1.1: 98 percent / p-TsOH / 12 h / Heating 2.1: 76 percent / O2; 5,10,15,20-tetrakis(pentafluorophenyl)porphine / CDCl3 / 6 h / -35 °C / Irradiation 3.1: L-methionine / acetonitrile; H2O / 0.25 h / 0 °C 3.2: 41 percent / NaBH4; DBU / tetrahydrofuran; H2O / 0.25 h / 0 °C View Scheme

1.1: 87 percent / LiAlH4 / diethyl ether 2.1: 91 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 3.1: 98 percent / p-TsOH / 12 h / Heating 4.1: 76 percent / O2; 5,10,15,20-tetrakis(pentafluorophenyl)porphine / CDCl3 / 6 h / -35 °C / Irradiation 5.1: L-methionine / acetonitrile; H2O / 0.25 h / 0 °C 5.2: 41 percent / NaBH4; DBU / tetrahydrofuran; H2O / 0.25 h / 0 °C View Scheme

1.1: 91 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 2.1: 98 percent / p-TsOH / 12 h / Heating 3.1: 76 percent / O2; 5,10,15,20-tetrakis(pentafluorophenyl)porphine / CDCl3 / 6 h / -35 °C / Irradiation 4.1: L-methionine / acetonitrile; H2O / 0.25 h / 0 °C 4.2: 41 percent / NaBH4; DBU / tetrahydrofuran; H2O / 0.25 h / 0 °C View Scheme

1.1: t-BuOK / dimethylformamide / 1 h / 20 °C 2.1: 87 percent / LiAlH4 / diethyl ether 3.1: 91 percent / oxalyl chloride; DMSO; Et3N / CH2Cl2 / -78 - 20 °C 4.1: 98 percent / p-TsOH / 12 h / Heating 5.1: 76 percent / O2; 5,10,15,20-tetrakis(pentafluorophenyl)porphine / CDCl3 / 6 h / -35 °C / Irradiation 6.1: L-methionine / acetonitrile; H2O / 0.25 h / 0 °C 6.2: 41 percent / NaBH4; DBU / tetrahydrofuran; H2O / 0.25 h / 0 °C View Scheme

1.1: 76 percent / O2; 5,10,15,20-tetrakis(pentafluorophenyl)porphine / CDCl3 / 6 h / -35 °C / Irradiation 2.1: L-methionine / acetonitrile; H2O / 0.25 h / 0 °C 2.2: 41 percent / NaBH4; DBU / tetrahydrofuran; H2O / 0.25 h / 0 °C View Scheme

1.1: p-TsOH / CH2Cl2 / 20 °C 2.1: 95 percent / imidazole / CH2Cl2 3.1: AgNO3; NCS 3.2: NaBH4 View Scheme