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Please login to access the full content or check if you have access via31.1.1.5.2.4 Variation 4: Reaction of Diazonium Hexafluoroantimonates
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Sandford, G., Science of Synthesis, (2007) 31, 63.
Although the Balz–Schiemann route, involving decomposition of diazonium tetrafluoroborate salts (see Section 31.1.1.5.2.3), has found widespread use in the synthesis of many fluoroarene derivatives, it has some limitations. If the diazonium salt is soluble in water as a result of the presence of hydroxy or carboxylic acid groups, it is difficult to purify and yields are dramatically reduced, while electron-withdrawing groups, such as nitro groups, significantly impede the decomposition process. Other diazonium salts with different counterions can be synthesized, of which hexafluoroantimonate salts 58 are found to be the most effective alternatives to tetrafluoroborate systems (Scheme 32).[153] Hexafluoroantimonate salts are readily prepared, highly insoluble in water, and decompose at lower temperatures than the corresponding tetrafluoroborates. Consequently, yields of fluoroarene systems 59 bearing electron-withdrawing groups are increased when diazonium hexafluoroantimonates are used instead of the usual tetrafluoroborate precursors.
Meeeee 88 Meeeeeeee Meeeeee Meeeeeeeeeeee ee Meeeeeeee Meeeeeeeeeeeeeeeeeee Meeee[888]
Me8 | Meee (°M) | Meeee (%) | Mee |
---|---|---|---|
Me | 88 | 88 | [888] |
8-Mee | 88 | 88 | [888] |
8-Mee | 88 | 88 | [888] |
8-Mee | 888 | 88 | [888] |
8-MM8MM8M8 | 888 | 88 | [888] |
8-MM8MM8M8 | 888 | 88 | [888] |
8-MM8MM8M8 | 888 | 88 | [888] |
8-M8MM8M8 | 888 | 88 | [888] |
8-M8MM8M8 | 888 | 88 | [888] |
8-M8MM8M8 | 888 | 88 | [888] |
8-MeMM8M8 | 888 | 88 | [888] |
8,8-M8M8M8 | 888 | 88 | [888] |
8,8-M8M8M8 | 888 | 88 | [888] |
Meeeeeeeeeee Meeeeeeee
8-Meeeeeeeeeeee (88, Me8 = 8-Mee); Meeeeee Meeeeeeee:[888]
MeMM8 (8.88 e, 88 eeee) eee eeeee ee e eeeeee eeee ee 8-eeeeeeeee (8.8 e, 88 eeee) ee M8M (8 eM) eee eee MMe (88 eM) ee −8°M. Mee eeeeeee eee eeeeeee eee 88 eee ee −8°M, eee 88% ee MMeM8 (88 eM) eee eeeee eeeeeeee eeee eeeeeeee. Mee eeeeeeeee eeee eeee eeeeeeeeeeee eee eeeeeeeee ee eeeeeeeeee, eeeeee eeee eeee M8M (88 eM) eee Me8M (88 eM), eee eeeee eeeee eeeeeee eeeeeeee. M eeeeeeeeee ee eee eeeeeeeeeee ee eeeee eeeeeee (888 eM) eee eeeeee ee e eeeee eeeeee eeee e eeeeee eeeeeeeee eeeee eeeeeeeeeeeee eee eeeeeeee. Mee eeeeeee eee eeeeeeee eee eeeeeeeee eeee eee ee MMe (8 × 88 eM), eee eee eeee eeeeeeee eeee eeeee ee eee eeeee eeeeeeeee ee eee eeeee. Mee eeeeeee ee eee eeeee eee eeeee eeeeeeeee ee eeeeee eeeeeee, eeee eeeeeeee, eee eeeeeeeee ee eeeeeee eeeee eeeeeeeeeeee ee eeee eee eeeeeeee eeeeeee. Mee eeeeeee eeeeeeeeee eee eeeeeeeee eeee MeMe eee eeee eeeeeeeee eeee Me8M (8 × 88 eM), eeeee (MeMM8), eee eeeeeeeee; eeeee: 8.8 e (88%); ee 888°M/8 eee.
References
[153] | Meeeeee, M.; Meeeeeeeee, M., M. Meee. Mee. M, (8888), 8888. |
Meeeeee Meeeeeeeeee
- 8.Meeeee-Meee, (8888) M 88e8, 888.