An investigation into the use of phase-transfer catalysis for the [2,3]-sigmatropic rearrangement of allyloxy carbonyl compounds is described. Initial studies focused on identifying viable substrate classes that would undergo selective [2,3]-rearrangement under phase-transfer catalysis. Under certain conditions, the [2,3]-sigmatropic rearrangement of allyloxy carbonyl compounds takes place in the presence of a phase-transfer agent, providing a rare example of a phase-transfer-catalyzed unimolecular reaction. In the course of this investigation, it was found that catalysis is dependent on several variables including base concentration, catalyst structure, and substrate lipophilicity. Preliminary testing of chiral, nonracemic phase-transfer catalysts has shown promising levels of enantioselectivity for future development.

The conjugate addition of acyl anion equivalents derived from 2-silyl-1,3-dithianes to α,β-unsaturated ketones and esters has been achieved using a substoichiometric amount of TBAF. High yields and short reaction times are observed for the addition of aryl-1,3-dithianes to a variety of cyclic and acyclic α,β-unsaturated carbonyl acceptors. Observation of the reactive anion by (13)C NMR spectroscopy and extension to an asymmetric variant is also presented.

Conjugate addition of acyl anion equivalents derived from 2‐silyl‐1,3‐dithianes to α,β‐unsaturated ketones and esters is achieved using readily available Bu4NF as catalyst.

The asymmetric [2,3]‐sigmatropic rearrangement of cyclic (allyloxy)carbonyl compounds (II) and (IV) in the presence of chiral phase transfer catalysts such as (I) is presented.