1-Alkenyl-1,1-heterobimetallics are potentially very useful in stereoselective organic synthesis, but are relatively unexplored. Introduced herein is a practical application of 1-alkenyl-1,1-heterobimetallic intermediates in the synthesis of versatile cyclopropyl alcohol boronate esters, which are valuable building blocks. Thus, hydroboration of 1-alkynyl-1-boronate esters with dicyclohexylborane generates 1-alkenyl-1,1-diboro species. In situ transmetalation with dialkylzinc reagents furnishes 1-alkenyl-1,1-borozinc heterobimetallic intermediates. Addition of the more reactive Zn–C bond to aldehydes generates the key B(pin) substituted allylic alkoxide intermediates. An in situ alkoxide directed cyclopropanation proceeds with the formation of two more C–C bonds, affording cyclopropyl alcohol boronate esters with three new stereocenters in 58–89% isolated yields and excellent diastereoselectivities (>15:1 dr). Oxidation of the B–C bond provides trisubstituted α-hydroxycyclopropyl carbinols as single diastereomers in excellent yields (75–93%). Facile pinacol-type rearrangement of the α-hydroxycyclopropyl carbinols provides access to both cis- and trans-2,3-disubstituted cyclobutanones with high stereoselectivity (>17:1 dr in most cases) from a common starting material. This methodology has been applied in the synthesis of quercus lactones A and B.

The combination of aryl bromides, allylbenzene, base and a palladium catalyst usually results in a Heck reaction. Herein we combine these same reagents, but override the Heck pathway by employing a strong base. In the presence of LiN(SiMe3)2, allylbenzene derivatives undergo reversible deprotonation. Transmetallation of the resulting allyllithium intermediate to LPdAr(Br) and reductive elimination provide the 1,1-diarylprop-2-enes, which are not accessible via the Heck reaction. The regioselectivity in this deprotonative cross-coupling process is catalyst-controlled and very high.

Diarylmethylamines are key intermediates and products in the pharmaceutical industry. Herein we disclose a novel method toward the synthesis of these important compounds via C–H functionalization. Presented is a reversible deprotonation of N-Boc benzylalkylamines at the benzylic C–H with in situ arylation by a NiXant-Phos-based palladium catalyst (50–93% yield, 29 examples). The method is also successful with N-Boc-tetrahydroisoquinolines. The advantages of this method are it avoids strong bases, low temperatures, and the need to transmetallate to main group metals for the coupling.