Organic Synthesis

Homoallylation with cyclopropanated allylation reagents

Although it is well known that allylboron reagents react stereospecifically with aldehydes, though cyclohexane chair transition states, we recently discovered that the corresponding cyclopropanated reagents react analogously, following a similar stereochemical logic: 

These reactions are robustly stereospecific, enabling reagent-controlled installation of the desired stereochemical pattern: 

The motif installed by this method is difficult to produce enantioselectively through other methods, and enables stremlined access to natural products: 

Recently, we have introduced reagents containing multiple sterocenters (α- and γ- stereochemistry, cis vs. trans cyclopropane). Strategic combination of these elements selective access to E- or Z- alkenes, and shown that they undergo photocycloaddition in flow to produce natural product-like scaffolds.