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2.6.3.1.2 Addition of Achiral Ylides to Chiral Imines

DOI: 10.1055/sos-SD-202-00130

Aggarwal, V. K.; McGarrigle, E. M.; Shaw, M. A.Science of Synthesis: Stereoselective Synthesis, (20112335.

The use of a chiral protecting group on the imine nitrogen can result in control of the configuration of the only stereocenter being formed in the reactions of trimethylsulfonium and trimethylsulfoxonium ylides.[‌86‌] Interestingly, trimethylsulfonium and trimethylsulfoxonium ylides, derived from sulfonium salts 45 and 46, respectively, exhibit the opposite diastereoselectivity from one another in this chemistry. More recently, this chemistry has been extended to reactions of semistabilized ylides such as that derived from sulfonium salt 48.[‌87‌,‌88‌] Chiral tert-butylsulfinyl groups have proven to be the most useful groups for this purpose, although other sulfinyl groups[‌89‌,‌90‌] and chiral phosphonates[‌91‌] have also been employed. Examples, forming 1-(tert-butylsulfinyl)aziridines 47 and 49, are given in Scheme 28.

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