Electrophilic carboxylation of alkenes

In the presence of 1.2 equivalents of boron trichloride 2,2-dichloro-1,3-benzodioxol (2) reacts with alkenes 4 to form 1:1 addition products 6, which are converted into the unsaturated tert-butyl esters 7 on treatment with potassium tert-butoxide. In the presence of ZnCl2, these reactions do not usually terminate at the 1:1-product stage, and 2,2-disubstituted 1,3-benzodioxols 5 are formed by reaction of 2 with two equivalents of 4a-f

Trifluoromethyl ethers – synthesis and properties of an unusual substituent

After nitrogen, fluorine is probably the next most favorite hetero-atom for incorporation into small molecules in life science-oriented research. This review focuses on a particular fluorinated substituent, the trifluoromethoxy group, which is finding increased utility as a substituent in bioactives, but it is still perhaps the least well understood fluorine substituent in currency. The present review will give an overview of the synthesis, properties and reactivity of this important substituent