Cyclopropane formation under frustrated Lewis pair conditions
Sergei Krupski1, Gerald Kehr1, Constantin G Daniliuc1
1Organisch-Chemisches Institut, Universität Münster, Corrensstrasse 40, 48149 Münster, Germany. erker@uni-muenster.de.
Chemical Communications (Cambridge, England)
|January 12, 2016
Summary
This study details the reaction of a phosphine with boron compounds, forming a cyclopropane derivative. A stable phosphiranium/borate zwitterion was then isolated and characterized.
Area of Science:
- Organophosphorus chemistry
- Boron chemistry
- Cycloaddition reactions
Background:
- Allyldimesitylphosphane derivatives are versatile synthetic intermediates.
- Reactions involving boron reagents can lead to novel organometallic structures.
Purpose of the Study:
- To investigate the reactivity of a -CH2OSiMe3 substituted allyldimesitylphosphane with boron compounds.
- To synthesize and characterize novel phosphine-boron adducts and cyclopropane derivatives.
Main Methods:
- Reaction of allyldimesitylphosphane with bis(pentafluorophenyl)borane (HB(C6F5)2).
- Subsequent reaction with tris(pentafluorophenyl)borane (B(C6F5)3).
- Isolation and X-ray diffraction characterization of the resulting zwitterion.
Main Results:
- A hydroboration/elimination sequence yielded a phosphinomethyl substituted cyclopropane.
- A stable phosphiranium/borate zwitterion was formed upon addition of B(C6F5)3.
- The zwitterion structure was confirmed by X-ray diffraction analysis.
Conclusions:
- The reaction pathway involves a likely phosphiranium intermediate.
- Stable phosphiranium/borate zwitterions can be synthesized and characterized.
- This work expands the understanding of phosphine-boron interactions and cyclopropane formation.
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