Chiral compounds 3,3 -sigmatropic rearrangement

Well known carbanionic sigmatropic rearrangements, applied to mixed P and S compounds, regio- and/or stereoselectively lead to new (a-sulfanylalkyl) or P-sulfanylaryl) phosphonates, phosphine oxides, or phosphorodiamidates. In these difunctional compounds, chirality can be either introduced on the phosphorus, on the a-carbon, or on the sulfur atom. 

Asymmetric ylide reactions such as epoxidation, cyclopropanation, aziridination, [2,3]-sigmatropic rearrangement and alkenation can be carried out with chiral ylide (reagent-controlled asymmetric induction) or a chiral C=X compound (substrate-controlled asymmetric epoxidations). Non-racemic epoxides are significant intermediates in the synthesis of, for instance, pharmaceuticals and agrochemicals. 

The sulfur ylides 254 used in the stereoselective [2,3]-sigmatropic rearrangement are generated by copper(I)-catalyzed Doyle-Kirmse reaction of aryl sulfides 253 and diazo compounds bearing Oppolzer s camphor sultam auxiliary 252 in the presence of chiral diamine ligand S, S)-259 <05JA15016>. These intermediate ylides undergo spontaneous... 

A review which covers sigmatropic rearrangements in addition to Diels-Alder reactions, 1,3-dipolar cycloadditions, electrocyclic reactions, and ene reactions has appeared. The stereochemistry of [3,3]-sigmatropic reactions of chiral carbon compounds has been reviewed, as have diastereoselective Claisen rearrangements of substrates bearing chiral auxiliary and enantioselective variants of achiral substrates. Examples of [3,3]-sigmatropic rearrangements used in the synthesis of various types of 3-chromene derivatives have been reviewed. ... 

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