A highly diastereoselective one of these features the oxidation of an N-sulfinyl group into an N-Tosyl group which undergoes a 6 member transition state, and yields a product similar to that of the Wenker synthesis.  This term is also used to describe reactions which proceed in the presence cinchona alkaloids and a chiral Lewis acids catalyst to form chiral C-C bonds. In addtition to those variations of Darzens reaction, Baylis-Hillman reaction and the Henry and Michael reactions this term is most famously used to describe a reaction where the nitrogen atom is double bonded to a carbon atom on the diene or the dienophile, a form of the Diels Alder  reaction. For fifteen points, identify this
A highly diastereoselective one of these features the oxidation of an N-sulfinyl group into an N-Tosyl group which undergoes a 6 member transition state, and yields a product similar to that of the Wenker synthesis.  This term is also used to describe reactions which proceed in the presence cinchona alkaloids and a chiral Lewis acids catalyst to form chiral C-C bonds. In addtition to those variations of Darzens reaction, Baylis-Hillman reaction and the Henry and Michael reactions this term is most famously used to describe a reaction where the nitrogen atom is double bonded to a carbon atom on the diene or the dienophile, a form of the Diels Alder  reaction. For fifteen points, identify this three letter word which describes reactions using imines.
A highly diastereoselective one of these features the oxidation of an N-sulfinyl group into an N-Tosyl group which undergoes a 6 member transition state, and yields a product similar to that of the Wenker synthesis.  
{aza} or {aza modification} or {aza} reaction (4) [accept "{Darzens reaction}" until mentioned; prompt on "{asymmetric synthesis}" until "{chiral C}-{C bonds}"]