Abstract
Allylboration and crotylboration are well-researched chemical processes that
yield stereocontrolled products via allylboronate addition to aldehydes. Similarly,
homoallylboration and homocrotylboration can be achieved with cyclopropylcarbinyl boronate
additions to reactions with a broad range of aromatic and aliphatic aldehydes, selectively
producing bishomoallyic alcohol products. The products then serve as scaffolds for natural
products and pharmaceutically significant compounds, enabling more efficient synthetic pathways.
This work focuses on the homoallylation of aldehydes with 1,2,3-trisubstituted
cyclopropylcarbinyl propanediol boronic esters, resulting in a bishomoallylic alcohol product with
three contiguous stereocenters. The novel 1,2,3-trisubstituted cyclopropylcarbinyl propanediol
boronic esters were first prepared using an unselective three-step synthetic pathway and then
synthesized selectively using three complementary routes. Homoallylation with both aromatic and
aliphatic aldehydes has been achieved with two of the 1,2,3-trisubstituted cyclopropylcarbinyl
propanediol boronic esters, and studies are ongoing to fully characterize the stereochemistry of the
products. The application of these novel reagents for homoallylation offers a new perspective on
the reactivity and selectivity of the reaction. This has thus established the basis for potential future
studies, enabling the exploration of various applications in total synthesis.