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Facile Preparation of Ultrafine Aluminum Hydroxide Particles with or without Mesoporous MCM-41 in Ambient Environments
Published on: May 11, 2017
Aluminumoxyhydride: improved synthesis and application as a selective reducing agent.
Brij B Tewari1, Sukesh Shekar, Longchuan Huang
1Department of Chemistry, Florida Institute of Technology, 150 West University Boulevard, Melbourne, Florida 32901, USA.
Inorganic Chemistry
|October 13, 2006
Summary
Aluminumoxyhydride (HAlO) can be synthesized as a stable powder or a reactive suspension. This reagent selectively reduces aldehydes and ketones to alcohols, proving useful in organic synthesis.
Area of Science:
- Organometallic Chemistry
- Synthetic Organic Chemistry
- Materials Science
Background:
- Aluminum hydride derivatives are valuable reducing agents in organic synthesis.
- The synthesis and application of aluminumoxyhydride (HAlO) have been explored.
- Previous methods produced insoluble HAlO, limiting its synthetic utility.
Purpose of the Study:
- To develop a reliable method for synthesizing aluminumoxyhydride (HAlO) suitable for synthetic applications.
- To characterize the properties and reactivity of HAlO suspensions.
- To evaluate the chemoselectivity of HAlO as a reducing agent.
Main Methods:
- Reaction of aluminum hydride precursors (H3Al.NMe3 or LiAlH4) with siloxanes ((Me2HSi)2O) or stannoxanes ((Bu3Sn)2O).
- Purification of HAlO via precipitation and isolation.
- Preparation of HAlO suspensions in tetrahydrofuran (THF) using LiAlH4, Me3SiCl, and (Me2HSi)2O, followed by heating.
Main Results:
- Amorphous, colorless, insoluble aluminumoxyhydride (HAlO) powder was successfully synthesized.
- The highest purity HAlO was obtained from the reaction of H3Al.NMe3 with (Me2HSi)2O.
- HAlO suspensions (0.4-0.5 M active hydride) were prepared from commercial reagents and selectively reduce aldehydes and ketones to alcohols in the presence of other functional groups.
Conclusions:
- Aluminumoxyhydride (HAlO) can be prepared in both powder and suspension forms.
- HAlO suspensions offer a practical and selective reducing agent for carbonyl compounds in organic synthesis.
- The developed method provides a convenient route to HAlO for various synthetic applications.
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