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Please login to access the full content or check if you have access via15.1.1.1.5.1.1 Method 1: Pyridin-3-ols from (2-Azaallenyl)pentacarbonylchromium Complexes, Alkynes, and Carbon Monoxide
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Spitzner, D., Science of Synthesis, (2005) 15, 38.
Condensation of the aminocarbene–chromium complex (Fischer complex) 106 with benzaldehyde, using titanium(IV) chloride/triethylamine as catalyst, gives the (2-azaallenyl)pentacarbonylchromium complex 107 (Scheme 38).[165] This complex cyclizes under neutral conditions at 80°C (sealed tube) with an alkyne to give a mixture of the corresponding pyridin-3-ol 108 and 1H-pyrrole 109;[166] carbon monoxide is provided by the pentacarbonylchromium moiety. (Trimethylsilyl)acetylene (R1 = H; R2 = TMS) gives mainly the corresponding pyridine, whereas most other alkynes give a mixture or only the 1H-pyrrole.
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References
| [165] | Meeeee, M.; Meeeeee, M.; Meüeee, M.; Meee, M., Meee. Mee., (8888) 888, 888. |
| [166] | Meeeee, M.; Meeeee, M., M. Meeeeeeee. Meee., (8888) 888, M8. |
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