Me 2 (CH 2 Cl)SiCF 3 Facilitated Tandem Synthesis of Oxasilacycles Featuring a Trifluoromethyl Group.

An unprecedented tandem trifluoromethylsilylation/intramolecular S N 2 substitution sequence was realized by using bifunctional reagent Me 2 (CH 2 Cl)SiCF 3 , allowing efficient construction of valuable trifluoromethylated oxasilacyclohexanes that are difficult to access by known methods. Initial attempts into developing asymmetric variant reveal that using cinchonine-derived dimeric PTC catalyst could afford chiral oxasilacyclohexanes in up to 92% enantiomeric excess.