## 2 Experimental Section
### Procedure for the Preparation of N-Phosphinylamines **1**
6 h) and then stirred at room temperature for 14 h. After completion of the reaction (monitored by TLC), the mixture was passed through a small column of silica gel, the column was eluted with ethyl acetate and the combined organic phases were concentrated under vacuum. The obtained residue was purified by column chromatography (silica gel, hexane/acetone 9:1), yielding the expected reduction products **2** in the yields indicated in Table 2. Phosphinamides **2** were analyzed by HPLC on a ChiralCel OD-H column using a 254 nm UV detector, 10% \(i\)-PrOH in hexane as eluent and a flow rate of 0.5 mL/min, giving the enantiomeric excesses (ee's) indicated in Table 2. The retention times were: 16.5 (\(R\)) and 23.4 (\(S\)) for **2a** (OD-H column), 13.9 (\(R\)) and 18.9 (\(S\)) for **2b** (OD-H column), 12.7 (\(R\)) and 28.1 (\(S\)) for **2c** (Chiralpak AS-H column, 20% \(i\)-PrOH in hexane as eluent and a flow rate of 1.0 mL/min). For every product **2**, the absolute configuration of the major enantiomer was assigned according to the HPLC retention times of the two enantiomers described in the literature under the same conditions [45,46]. The corresponding physical and spectroscopic data follow:  
**(_R_)-**N**-**(1-Phenyltophy)diphenylphosphinamide (2a)**[23]: white solid; mp 166-168 \({}^{\circ}\)C; \([\alpha]^{20}\)\({}^{+}\)32.0 (\(c\) 1.1, CH\({}_{2}\)Cl\({}_{2}\), 82% ee) {literature [23] [\(\alpha\)]\({}^{20}\)\({}_{\rm D}\) +28.5 (\(c\) 1.0, CH\({}_{2}\)Cl\({}_{2}\), 75% ee)}; IR (KBr) 3159, 3059, 1179 cm\({}^{-1}\); \({}^{1}\)H NMR (300 MHz, CDCl\({}_{3}\)) \(\delta\) 1.58 (3H, d, \(J\) = 6.7 Hz), 3.14-3.21 (1H, m), 4.33-4.48 (1H, m), 7.25-7.50 and 7.78-7.95 (11H and 4H, respectively, 2 m); \({}^{13}\)C NMR (75 MHz, CDCl\({}_{3}\)) \(\delta\) 26.3 (d, \(J\) = 3.0 Hz), 51.3, 126.0, 127.2, 128.3, 128.4, 128.47, 128.56, 128.59, 131.7, 131.82, 131.86, 132.0, 132.1, 132.5, 132.6, 145.1 (d, \(J\) = 6.2 Hz); \(m\)/z 321 (M\({}^{+}\), 5%), 307 (19), 306 (72), 202 (22), 201 (100), 120 (98), 77 (34). **(_R_)-**N**-**(1-Phenylpropyl)diphenylphosphinamide (2b)**[23]: white solid; mp 153-155 \({}^{\circ}\)C; \([\alpha]^{20}\)\({}_{\rm D}\) +26.0 (\(c\) 1.0, MeOH, 82% ee) {literature [23] [\(\alpha\)]\({}^{20}\)\({}_{\rm D}\) +31.3 (\(c\) 1.35, MeOH, 81% ee)}; IR (KBr) 3145, 3060, 1198 cm\({}^{-1}\); \({}^{1}\)H NMR (300 MHz, CDCl\({}_{3}\)) \(\delta\) 0.77 (3H, t, \(J\) = 7.5 Hz), 1.75-2.10 (2H, m), 3.12-3.35 (1H, m), 4.02-4.20 (1H, m), 7.10-7.55 and 7.70-7.95 (11H and 4H, respectively, 2 m); \({}^{13}\)C NMR (75 MHz, CDCl\({}_{3}\)) \(\delta\) 10.5, 32.5 (d, \(J\) = 3.1 Hz), 57.1, 126.5, 127.1, 128.2, 128.3, 128.4, 128.5, 131.9, 132.5, 132.6, 143.5 (d, \(J\) = 5.4 Hz); \(m\)/z 335 (M\({}^{+}\), 3%), 307 (21), 306 (100), 201 (53), 134 (16), 77 (22). **(_R_)-**N**-**[1-(_p_-Chlorophenyl)ethyl]diphenylphosphinamide (2c)**[42]: white solid; mp 161-163 \({}^{\circ}\)C; \([\alpha]^{20}\)\({}_{\rm D}\) +60.5 (\(c\) 1.0, MeOH, 80% ee) {literature for _ent-_**2c**[28] [\(\alpha\)]\({}^{20}\)\({}_{\rm D}\) -73.4 (\(c\) 1.14, MeOH, 94% ee)}; IR (KBr) 3152, 3062, 1189 cm\({}^{-1}\); \({}^{1}\)H NMR (400 MHz, CDCl\({}_{3}\)) \(\delta\) 1.54 (3H, d, \(J\) = 6.9 Hz), 3.15-3.34 (1H, m), 4.29-4.45 (1H, m), 7.19-7.30, 7.38-7.51, 7.78-7.93 (4H, 6H and 4H, respectively, 3 m); \({}^{13}\)C NMR (100 MHz, CDCl\({}_{3}\)) \(\delta\) 25.7 (d, \(J\) = 3.8 Hz), 50.3, 127.4, 128.2, 128.3, 128.4, 128.6, 131.4, 132.8, 133.5, 143.5 (d, \(J\) = 6.1 Hz); \(m\)/z 357 (M\({}^{+}\)+2, \(<\)1%), 355 (M\({}^{+}\), 3), 340 (24), 306 (100), 202 (16), 201 (70), 154 (100), 77 (26).