Iridium-Catalyzed Asymmetric Alkoxy-allylation of Aldehydes

Significance

There are numerous highly enantio­selective methods for the allylation of aldehydes. If the allylating agent is appropriately substituted, vicinal stereocenters can be generated. One such highly desirable transformation is the addition of alkoxyallyl nucleophiles to create synthetically useful vicinal diols. Few such examples exist in the literature, and all thus far require a stoichiometric amount of allylmetal reagents. Moreover, these ­reactions are limited to syn-addition products. The authors present the first example of a catalytic enantioselective anti-α-alkoxyallylation. An iridium-SEGPHOS catalyst is used, and readily available acrolein gem-dibenzoate serves as the inexpensive allyl source.