Iminium Salts in Solid-State Syntheses Giving 100% Yield
✍ Scribed by Gerd Kaupp; Jens Schmeyers; Juergen Boy
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 354 KB
- Volume
- 342
- Category
- Article
- ISSN
- 1615-4150
No coin nor oath required. For personal study only.
✦ Synopsis
Organic reactions that give 100% yield and do not require workup are environmentally benign and particularly versatile. Their use should also be considered if highly sensitive reagents and products are involved. Indeed, waste-free reactions occur frequently in solidstate iminium salt chemistry [1]. Mechanistic knowledge from supermicroscopic investigations (AFM and SNOM) verify three-step mechanisms that consist of phase rebuilding, phase transformation and crystal disintegration in solid-state reactions without liquid phase and far-reaching anisotropic molecular movements. It is thus comprehensible that gas-solid and solid-solid reactions tend to be complete and selective with the aid of crystal packing effects. It is essential that mechanical treatment (grinding, milling, ultrasound) reestablish fresh contacts of reacting crystals over and over again for the completion of solid-solid reactions to occur [2]. Anyhow, solid-state reactions have not yet been included in organic textbooks despite repeated reports on their environmental benefits and their superior practicability due to the avoidance of work-up and wastes [3,4,5]. Anyhow, many published examples using commonly available reagents in stoichiometric quantities would deserve such inclusion, because they are particularly easy, save work and energy and are just better, if they give 100% yield without workup. Even liquids can be solidified in various instances by cooling or complexa-