Table 3. Preparation of 2,5-Diarylpyrrolidine 23 and 1-Nitroso-2,5-diarylpyrrolidine 24.

| entry | R | refa | temp (°C) | time (h) | yieldb (%) | refa | temp (°C) | time (h) | yieldb (%) |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 4-MeOC6H4 | 23a | 0c | 1 | 82 | 24a | 0 | 2 | 96 |
| 2 | 2-naphthyl | 23f | 0d | 6 | 81 | 24f | 22 | 2 | 92 |
| 3 | 3,5-Me2C6H3 | 23g | 0d | 2 | 86 | 24g | 22 | 20 | 96 |
| 4 | 3,5-Ph2C6H3 | 23h | 0d | 6 | 93 | 24h | 22 | 12 | 93 |
| 5 | 2-tolyl | 23i | 0c | 2 | 97f | 24i | 22 | 12 | 95 |
| 6 | 5-Me-2-thienyl | 23j | 200e | 18 | ∼64g | 24j | 0 | 0.25 | 57h |
Reference number for compound.
Yield of chromatographed product.
Reaction condition A (TMSI) was used.
Reaction condition B (TFA) was used.
Boc group was removed by heating at 200 °C under argon.
Yield of crude product.
Cannot completely purify by chromatography.
Yield after two steps.