Aldehydes trimethylsilyl cyanide added

An example of this type of effort is as follows. Complexation of the carbonyl oxygen of N/(-dibenzyl-a-amino aldehydes wiA Lewis acids such as BF3, ZnBr2 or SnCU, followed by ad tion of trimethylsilyl cyanide leads to adducts formed by a nonchelation-controlled process. Complexation with TiCU or MgBr2 affords the opposite stereochemistry preferentially, tl ugh a chelation-controlled process (Scheme 1). ... 

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