SilÂ·yl ether protecting groups can be removed by using a  luoride salt of one of these molecules.
Application of sodium amide to a benÂ·zylÂ·ic version of these compounds can lead to ortho alkylation in the Sommelet-Hauser rearrangement. They don't contain sulfur, but these molecules can undergo a 1,2 shi t in the presence of a strong base in the Stevens rearrangement. SilÂ·yl ether protecting groups can be removed by using a  luoride salt of one of these molecules. They're not crown ethers, but salts of these molecules are the most commonly used phase transfer catalysts. One of these compounds is generated with the use of methyl iodide and then eliminated with silver oxide to give the less substituted alkene in the Hofmann elimination. They are most easily obtained by reacting a tertiary amine with an alkyl halide in an SN2 reaction. For 10 points, name these species that contain a hypervalent, positively charged nitrogen atom.
Application of sodium amide to a benÂ·zylÂ·ic version of these compounds can lead to ortho alkylation in the Sommelet-Hauser rearrangement.
quaternary ammonium cations [or quarternary amines; or quaternary ammonium salts]