As part of a long-running project in the group of Prof Varinder Aggarwal FRS at the University of Bristol we have been involved in research on the development of chiral sulfur ylides for asymmetric epoxidation, aziridination and epoxidation. A major success story is the development of an easily accessible chiral sulfide which gives high enantioselectivities in epoxidations and aziridinations. 
The sulfide can be made from limonene and sulfur in just one step making it cheap to make. It has also become commercially available as a result of our work (TCI cat no T2578 & T2579; Aldrich 766429).
See: J Am Chem Soc 2013, 135, 11951. DOI: 10.1021/ja405073w
J Am Chem Soc 2010, 132, 1828–1830. DOI: 10.1021/ja9100276
We have also worked on improving mechanistic understanding of ylide reactions. Recently isotopic labelling studies revealed how an intramolecular proton transfer was hampering some asymmetric cyclopropanations.
See J Am Chem Soc 2010, 132, 7626–7630. DOI: 10.1021/ja910631u
See the publications section for more published papers.
