A deprotonation pathway to reactive [B]CH2 boraalkenes

Karel Škoch; Chaohuang Chen; Constantin G Daniliuc; Gerald Kehr; Gerhard Erker

doi:10.1039/d2dt01193j

A deprotonation pathway to reactive [B]CH₂ boraalkenes

Dalton Trans. 2022 May 17;51(19):7695-7704. doi: 10.1039/d2dt01193j.

Authors

Karel Škoch¹, Chaohuang Chen¹, Constantin G Daniliuc¹, Gerald Kehr¹, Gerhard Erker¹

Affiliation

¹ Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraβe 40, 48149 Münster, Germany. erker@uni-muenster.de.

PMID: 35521694
DOI: 10.1039/d2dt01193j

Abstract

The BH compounds IMes(Ar^F)BH(NTf₂) (Ar^F: C₆F₅ or FpXyl) were converted to the IMes(Ar^F)BCH₂ boraalkenes in a three step reaction sequence of B-methylation with methyllithium, hydride abstraction and deprotonation. The BCH₂ boraalkenes reacted with elemental sulfur to give a thiaborirane product. They underwent [2+2] cycloaddition reactions with carbon dioxide or sulfur dioxide to give four-membered boron containing heterocycles. The boraalkenes added strongly Lewis acidic boranes at their CH₂ carbon atoms. The corresponding HB(C₆F₅)₂/boraalkene adduct reduced carbon monoxide to a -OCH(C₆F₅)- moiety inside a five-membered heterocycle at the B-CH₂-B template. The boraalkenes reacted with the [(Me₂S)AuCl] reagent to form the corresponding (boraalkene)AuCl complexes.