Iron-catalyzed cyclopropanation with glycine ethyl ester hydrochloride in water.

An iron-catalyzed cyclopropanation reaction of styrenes in aqueous media is disclosed that employs glycine ethyl ester hydrochloride in a tandem diazotization/cyclopropanation reaction. The products are accessed in good yields and good diastereoselectivity using readily available and inexpensive starting materials. Moreover, a wide range of transition metals may be used under these conditions, thus opening new opportunities for efficient carbene-transfer reactions under user-friendly conditions.