Catalytic Enantio- and Diastereoselective Formation of Beta-Sulfones: Ring-Strained Precursors for Enantioenriched Beta-Hydroxysulfonyl Derivatives

Link: http://www3.interscience.wiley.com/cgi-bin/abstract/114134109/ABSTRACT

From Prof. Rene Peters' group at ETH Zurich

The authors present the synthesis and utilization of reactive beta-sulfones from sulfenes and aldehyde. The authors were able to make the 4-membered sulfones in high d.r. and e.r. using chiral nucleophile as a catalyst and metal triflate as a co-catalyst and by varying reaction temperatures.
The key tactic of the synthesis includes the use of CCl3 as R' to stabilize the beta-sulfone compound. Upon successful synthesis of their sulfones, they also demonstrate that this compound can be used as a chiral building block in making various useful chiral compounds as shown in the schemes below (taken from their paper).

The other nice feature of CCl3 handle is the possibility of partial dechlorination. One can imagine that further cross-couplings or other reactions may be possible with these chlorine handles.

I think this is a very nice paper presenting some cool chemistry and, in the process, adding another valuable chiral building block to organic chemists' toolbox.