Palladium catalyzes the cyclopropanation of 2-substituted 1,1-diborylalkenes with (trimethylsilyl)diazomethane. The relative stereoselectivity is controlled via a carbene insertion sequence generating an exclusive anti conformation between the R and SiMe 3 substituents. Mixed 1,1-diborylalkenes also contributed to the formation of stereoselective B, B, Si-cyclopropanes. Orthogonal activation with NaO t Bu gives protodeborylation preferentially on the boron moiety syn to the aryl group. Further oxidation gives access to polyfunctional cyclopropyl alcohols with controlled enantioselectivity when chiral boryl motifs are involved.

Exchange of boryl moieties is possible between alkenylboranes and diboron reagents as a stereospecific cross-metathesis with formation of mixed diboron reagents. DFT calculations propose a mechanism with both symmetric and non-symmetric diboron reagents.

Regioselective borylcupration of borylated skipped (Z)-dienes generates diborylated alkylcopper species that are involved in an intramolecular stereospecific B/Cu 1,3-rearrangement by migration of Bpin moiety from C(sp 2 ) to C(sp 3 ). DFT mechanistic studies showed that boryl migration occurs through the formation of 4-membered boracycle intermediate with a moderate free-energy barrier. Moreover, the use of KOMe forms stable Lewis base adducts with Bpin moieties that blocks the reaction. Subsequently to the 1,3-boron shift, the in situ electrophilic trapping allows selective CÀ H, CÀ C and CÀ X bonds, followed by intramolecular cross coupling giving access to cyclic functionalized alkylidenecyclohexanes or alkylidenecyclobutanes.

The renaissance on the application of gem‐diborylalkanes from 2010, has allowed the conquest of new synthetic application towards C−C and C−N bond formation. The activation of gem‐diborylalkanes by Cu(I) catalysts, generates active borylalky copper(I) species that are able to trap several electrophilic reagents, in an efficient way. In addition, the modification of Cu(I) complexes with chiral ligands, induces asymmetric platforms towards the synthesis of enantioenriched organoboron compounds.

Regioselective borylcupration of borylated skipped (Z)‐dienes generates diborylated alkylcopper species that are involved in an intramolecular stereospecific B/Cu 1,3‐rearrangement by migration of Bpin moiety from C(sp2) to C(sp3). DFT mechanistic studies showed that boryl migration occurs through the formation of 4‐membered boracycle intermediate with a moderate free‐energy barrier. Moreover, the use of KOMe forms stable Lewis base adducts with Bpin moieties that blocks the reaction. Subsequently to the 1,3‐boron shift, the in situ electrophilic trapping allows selective C−H, C−C and C−X bonds, followed by intramolecular cross coupling giving access to cyclic functionalized alkylidenecyclohexanes or alkylidenecyclobutanes.