Table 2. Scope of the cascade applying sequential organocatalysis a .
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| Entry | R1 | R2 | A (step 1) | A (step 2) | Temp. (step 2) | t (h) | Product | Yield b (%) | dr c | ee d (%) |
| 1 | Me | Me | (S)-A | — | 40 °C | 24 | 6a | 73 | 7 : 1 | 99 |
| 2 | Me | H | (S)-A | — | 40 °C | 24 | 6b | 60 | 2 : 1 | 99 |
| 3 | Bn | Bn | (S)-A | (R)-A | 40 °C | 36 | 6c | 49 | >20 : 1 | 99 |
| 4 | nBu | nBu | (S)-A | (R)-A | rt | 72 | 6d | 45 | >20 : 1 | 99 |
| 5 | Et | Et | (S)-A | (R)-A | rt | 48 | 6e | 47 | >20 : 1 | 99 |
aExperiments performed on a 0.2 mmol scale following general procedure C. See ESI Section 5.1 for details.
bIsolated yield determined after FC.
cDetermined using 1H NMR analysis of the isolated compound.
dDetermined using chiral stationary phase UPC2.