Carbon tetrabromide, also known as tetrabromomethane, is a commercially available white solid which is stable at room temperature and can be easily handled. It is prepared either by the complete bromination of methane or by the reaction of tetrachloromethane with aluminum bromide. In combination with a tertiary phosphine, it has been used for the bromination of various functional groups, such as alcohols (Appel reaction),[ 1 ] N-heterocycles,[ 2 ] ethers,[ 3 ] and for converting aldehydes/ketones into 1,1-dibromoalkenes[ 4 ] or alkynes[ 5 ] (Corey–Fuchs reaction). In addition, carbon tetrabromide is a highly efficient catalyst for versatile reactions, including acylation of phenols, alcohols and thiols,[ 6 ] acetalization and tetrahydropyranylation[ 7 ] and oxidation of aromatic methyl ketones[ 8 ] or alkenes[ 9 ] to carboxylic acids under very mild conditions. Carbon tetrabromide can further promote the synthesis of thioureas and thiuram disulfides.[ 10 ] Apart from these applications, carbon tetrabromide is also used as a crystal growth[ 11 ] and chain transfer agent[ 12 ] in polymer chemistry.