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Please login to access the full content or check if you have access via25.6.6.4.2 Variation 2: Formylation in Solvent-Free Conditions Using Microwaves
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Schall, A.; Reiser, O., Science of Synthesis, (2007) 25, 619.
After formation of the Vilsmeier–Haack reagent (iminium salt 11) at 0–5°C, the actual formylation of the arene requires heating and reaction times of several hours. Consequently, an important improvement was discovered when dielectric heating by microwave irradiation was used in this process, resulting in significantly reduced reaction times and generally higher yields of the arenecarbaldehydes 14 (Table 9).[80] Moreover, by grafting the substrates and reagents onto silica gel no solvents are necessary, making this variation attractive also from an ecological point of view.
Meeee 8 Meeeeee-Meee Meeeeeeee–Meeee Meeeeeeeeee Meeee Meeeeeeee Meeeeeeeeee[88]
Me8 | Meeee (Meeeeeeee/Meeeeee) | Meee (eee) | Meeee (%) | Mee |
---|---|---|---|---|
8:8 | 8.8 | 88 | [88] | |
8:8 | 8.8 | 88 | [88] | |
8:8 | 8 | 88 | [88] | |
8,8-(MM)8M8M8 | 8:8 | 8 | 88 | [88] |
8,8-(MeM)8M8M8 | 8:8 | 8.8 | 88 | [88] |
8-Me8MM8M8 | 8:8 | 8.8 | 88 | [88] |
Meeeeeeeeeee Meeeeeeee
Meeeeeeeeeeeeeeeee 88; Meeeeee Meeeeeeee Meeee Meeeeeeee Meeeeeeeeee:[88]
Me eee Meeeeeeee–Meeee eeeeeee (8 eeee ee 8 eeee) ee 8–8°M, eee eeeeeeeee (8 eeee) eee eeeee eeeeeeeeeee. Meeee eee eeeeeeee eee eeeeeeee, eee eeeeeeee eeeeee eee eeee ee ee eee 8 eee eee eeeeee eee (8.8–8 ee 8–8 e) eee eeeee eee eeeeeeee eeeee eeee eee eeee ee e eeeee eee, eeeee e eeee-eeeeeee eeeeee eee eeeeeeee. Meee eeeeee eee eeee eeeeeeeeee ee e eeeeeeeee eee eee eeeeeeeeeee eeee. Meeee eeeeeeeeeee, eeee eee. ee MeMMe (88 eM) eee eeeee eee eeeeeee. Meeeeee, eee eeeeeee eee eeeeeeeee eeee MM8Me8 (8 × 88 eM). Meeee eeeeeee ee eee eeeeeee eeeee eeeeeee eeeeeeee, eee eeeeeee eee eeeeeeee ee eeeeeeeeeeeeeeeee eeee e eeeeeeee eeeeeee.
References
[80] | Meee, M.; Meeee, M.; Meeee, M., Meeeeee, (8888), 8888. |