Reduction of carbodiimides by a dialumane through insertion and cycloaddition
Lin Xiao1, Weixing Chen1, Lingyi Shen1
1Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China. zhaoyx@nwu.edu.cn.
Chemical Communications (Cambridge, England)
|May 12, 2020
Summary
Dialumane compounds react with carbodiimides via insertion or cycloaddition. Steric hindrance from bulkier carbodiimides directs the reaction toward formamidinate products.
Area of Science:
- Organometallic Chemistry
- Main Group Chemistry
Background:
- Dialumane compounds represent a unique class of low-valent aluminum species.
- Carbodiimides are versatile organic linkers with diverse reactivity.
Purpose of the Study:
- To investigate the reaction pathways of a specific dialumane with various carbodiimides.
- To understand the role of steric bulk in controlling the reaction outcome.
Main Methods:
- Synthesis and characterization of the dialumane precursor [L2-AlII-AlIIL2-].
- Reaction of the dialumane with different N,N'-disubstituted carbodiimides (R = Cy, iPr, Dipp, tBu).
- Spectroscopic analysis (NMR) and X-ray crystallography to elucidate product structures.
Main Results:
- Dialumane 1 reacts with less hindered carbodiimides (R=Cy, iPr) via insertion, [2+4] cycloaddition, and hydrogen transfer.
- Reactions with bulkier carbodiimides (R=Dipp, tBu) are sterically controlled.
- Sterically demanding carbodiimides exclusively yield formamidinate products.
Conclusions:
- The reactivity of dialumane is tunable by the steric properties of carbodiimides.
- Steric control is a key factor in directing the reaction pathway towards formamidinate formation.
- This study expands the known reactivity of low-valent aluminum species.
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