Ni-Catalyzed Reductive Allylation of α-Chloroboronates to Access Homoallylic Boronates

Abstract

The transition-metal-catalyzed allylation reaction is an efficient strategy for the construction of new carbon–carbon bonds alongside allyl or homoallylic functionalization. Herein we describe a Ni-catalyzed reductive allylation of α-chloroboronates to efficiently render the corresponding homoallylic boronates, which could be readily converted into valuable homoallylic alcohols or amines or 1,4-diboronates. This reaction features a broad substrate scope with good functional group compatibility that is complementary to the existing methods for the preparation of homoallylic boronates.

Ni-Catalyzed Radical-Promoted Defluoroalkylborylation of Trifluoromethyl Alkenes To Access gem-Difluorohomoallylic Boronates

“…On the basis of the above results and previous reports, ,,, we proposed a tentative reaction mechanism (Scheme ). Initially, a Ni­(II) species is reduced by Zn dust to generate Ni(0) species.…”

“…α-Haloboronates are multifunctional synthons in organic chemistry that provide direct access to diverse valuable and complex alkylboronates . Moreover, protocols of radical addition to α-trifluoromethyl alkenes for providing gem -difluorovinyl compounds have been well-developed. , Inspired by these results and our previous efforts on fluorine-containing organoboron chemistry, here, we disclose an efficient strategy for the construction of gem -difluorohomoallylic boronates through a Ni-catalyzed radical-promoted defluoroalkylborylation of α-trifluoromethyl alkenes with α-haloboronates under mild conditions (Scheme d).…”

Beyond classical sulfone chemistry: metal- and photocatalytic approaches for C–S bond functionalization of sulfones

“…More recently, Song 112 has described an alternative approach for the use of allyl sulfones as allylating reagents for electrophiles. The team reported on a reductive Ni-catalysed cross-coupling with α-chloroboronates that rendered the corresponding homoallylic boronates mediated by the presence of Zn (Scheme 58).…”

Palladium-catalyzed decarboxylative O-allylation of phenols with γ-methylidene-δ-valerolactones

“…3 One of the classical methods in the preparation of allyl aryl ethers is Williamson ether synthesis, 4 using phenoxide and highly activated, unstable allyl halides or tosylates as the starting materials, but a stoichiometric amount of strong bases are often required. In the past decades, transition-metal-catalyzed allylation has frequently been well employed when carbon, nitrogen and sulfur nucleophiles were used, 5 but phenol derivatives as soft nucleophiles still received less attention, because the allylation of phenols tends to be both O - and C -selective. Recently, some transition metal complexes ( e.g.…”