We
disclose a transmetalation-initiated Ni(I)-catalyzed regioselective
β,δ-vinylarylation of γ,δ-alkenyl α-cyanocarboxylic
esters with vinyl triflates and arylzinc reagents. This reaction proceeds
via contraction of six-membered nickellacycles to five-membered nickellacycles
to form carbon–carbon bonds at the nonclassical homovicinal
sites, and it provides expeditious access to a wide range of complex
aliphatic α-cyanoesters, α-cyanocarboxylic acids, dicarboxylic
acids, dicarboxylic acid monoamides, monocarboxylic acids, nitriles,
and spirolactones. Control, deuterium labeling, and crossover experiments
indicate that (i) the nickellacycle contraction occurs by β-H
elimination, followed by hydronickellation on transiently formed alkenes,
and (ii) the Ni species are stabilized as Ni-enolates.
We disclose a nickel‐catalyzed reaction, which enabled us to difunctionalize unactivated γ,δ‐alkenes in ketones with alkenyl triflates and arylboronic esters. The reaction was made feasible by the use of 5‐chloro‐8‐hydroxyquinoline as a ligand along with NiBr2⋅DME as a catalyst and LiOtBu as base. The reaction proceeded with a wide range of cyclic, acyclic, endocyclic and exocyclic alkenyl ketones, and electron‐rich and electron‐deficient arylboronate esters. The reaction also worked with both cyclic and acyclic alkenyl triflates. Control experiments indicate that carbonyl coordination is required for the reaction to proceed.
We disclose a Ni-catalyzed vicinal
alkylarylation of unactivated
alkenes in γ,δ-alkenylketimines with aryl halides and
alkylzinc reagents. The reaction produces γ-C(sp3)-branched δ-arylketones with the construction of two C(sp3)–C(sp3) and C(sp3)–C(sp2) bonds. Electron-deficient alkenes play crucial dual roles
as ligands to stabilize reaction intermediates and to increase catalytic
rates for the formation of C(sp3)–C(sp3) bonds. This alkene alkylarylation reaction is also effective for
secondary alkylzinc reagents and internal alkenes and proceeds with
a complete regio- and stereocontrol, affording products with up to
three contiguous all-carbon all-cis secondary stereocenters.
We
report a five-step synthesis of the biologically important 1,1-diarylalkane 1, a potential 5-lipoxygenase activating protein (FLAP) inhibitor
that was synthesized previously in 12 steps. In this synthesis, we
apply a three-component alkene dicarbofunctionalization reaction as
a key final step to assemble the potential FLAP inhibitor 1 from commercially available starting materials. In addition, we
also report the synthesis of a variety of new analogs of the inhibitor 1 and its regioisomer.
We disclose a Ni‐catalyzed regioselective dialkylation reaction of alkenylarenes with α‐halocarbonyls and alkylzinc reagents. The reaction produces γ‐arylated alkanecarbonyl compounds with the generation of two new C(sp3)−C(sp3) bonds at the vicinal carbons of alkenes. This reaction is effective for the use of primary, secondary and tertiary α‐halocarboxylic esters, amides and ketones in conjunction with primary and secondary alkylzinc reagents as the sources of two C(sp3) carbons for the dialkylation of terminal and cyclic internal alkenes.
We report a Cu(II)-catalyzed cyclization/coupling of alkenyl aldimines with arylzinc reagents to create indole-3-diarylmethane derivatives (Sapkota et al. ChemRxiv 2022,
We report a Cu(II)-catalyzed cyclization/coupling of alkenyl aldimines with arylzinc reagents to create complex indole-3-diarylmethane derivatives. The aldimines are readily available by simple dehydration, making the process a formal three-component reaction that strategically combines alkenyl aldehydes, anilines and arylzinc reagents to generate substituted indole-3-diarylmethane cores. Since the cyclization/coupling of alkenyl aldimines is unknown to date, the current method discloses an uncharted chemical space with regard to both the substrate and product diversity for this class of reaction.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.