Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Nickel-catalyzed, ring-forming aromatic C-H alkylations with unactivated alkyl halides.

ABSTRACT: The development of a nickel-catalyzed C-H alkylation of aromatic substrates with unactivated alkyl halides is described. This carbocyclization facilitates the synthesis of diverse fused ring systems from simple aromatic substrates and is an attractive alternative to traditional polar or radical-mediated ring formations. The present system uses unactivated primary and secondary alkyl bromides and chlorides, while avoiding the use of precious palladium catalysts and more reactive alkyl halides commonly used in related C-H alkylations.

SUBMITTER: Tercenio QD

PROVIDER: S-EPMC6690380 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Nickel-catalyzed, ring-forming aromatic C-H alkylations with unactivated alkyl halides.

Tercenio Quentin D QD Alexanian Erik J EJ

Tetrahedron 20190525 31

The development of a nickel-catalyzed C-H alkylation of aromatic substrates with unactivated alkyl halides is described. This carbocyclization facilitates the synthesis of diverse fused ring systems from simple aromatic substrates and is an attractive alternative to traditional polar or radical-mediated ring formations. The present system uses unactivated primary and secondary alkyl bromides and chlorides, while avoiding the use of precious palladium catalysts and more reactive alkyl halides com ...[more]

PMID: 31406389

Similar Datasets

Palladium-catalyzed, ring-forming aromatic C-H alkylations with unactivated alkyl halides.

Project description:A catalytic C-H alkylation using unactivated alkyl halides and a variety of arenes and heteroarenes is described. This ring-forming process is successful with a variety of unactivated primary and secondary alkyl halides, including those with ?-hydrogens. In contrast to standard polar or radical cyclizations of aromatic systems, electronic activation of the substrate is not required. The mild, catalytic reaction conditions are highly functional group tolerant and facilitate access to a diverse range of synthetically and medicinally important carbocyclic and heterocyclic systems.

| S-EPMC4401995 | biostudies-literature

Nickel-catalyzed carbon-carbon bond-forming reactions of unactivated tertiary alkyl halides: Suzuki arylations.

Project description:The first Suzuki cross-couplings of unactivated tertiary alkyl electrophiles are described. The method employs a readily accessible catalyst (NiBr(2)·diglyme/4,4'-di-tert-butyl-2,2'-bipyridine, both commercially available) and represents the initial example of the use of a group 10 catalyst to cross-couple unactivated tertiary electrophiles to form C-C bonds. This approach to the synthesis of all-carbon quaternary carbon centers does not suffer from isomerization of the alkyl group, in contrast with the umpolung strategy for this bond construction (cross-coupling of a tertiary alkylmetal with an aryl electrophile). Preliminary mechanistic studies are consistent with the generation of a radical intermediate along the reaction pathway.

| S-EPMC3547142 | biostudies-literature

Nickel-catalyzed cross-coupling of potassium aryl- and heteroaryltrifluoroborates with unactivated alkyl halides.

Project description:A method for the cross-coupling of alkyl electrophiles with various potassium aryl- and heteroaryltrifluoroborates has been developed. Nearly stoichiometric amounts of organoboron species could be employed to cross-couple a large variety of challenging heteroaryl nucleophiles. Several functional groups were tolerated on both the electrophilic and the nucleophilic partners. Chemoselective reactivity of C(sp(3))-Br bonds in the presence of C(sp(2))-Br bonds was achieved.

| S-EPMC3075421 | biostudies-literature

Nickel-catalyzed electrochemical carboxylation of unactivated aryl and alkyl halides with CO<sub>2</sub>.

Project description:Electrochemical catalytic reductive cross couplings are powerful and sustainable methods to construct C-C bonds by using electron as the clean reductant. However, activated substrates are used in most cases. Herein, we report a general and practical electro-reductive Ni-catalytic system, realizing the electrocatalytic carboxylation of unactivated aryl chlorides and alkyl bromides with CO2. A variety of unactivated aryl bromides, iodides and sulfonates can also undergo such a reaction smoothly. Notably, we also realize the catalytic electrochemical carboxylation of aryl (pseudo)halides with CO2 avoiding the use of sacrificial electrodes. Moreover, this sustainable and economic strategy with electron as the clean reductant features mild conditions, inexpensive catalyst, safe and cheap electrodes, good functional group tolerance and broad substrate scope. Mechanistic investigations indicate that the reaction might proceed via oxidative addition of aryl halides to Ni(0) complex, the reduction of aryl-Ni(II) adduct to the Ni(I) species and following carboxylation with CO2.

| S-EPMC8648755 | biostudies-literature

Nickel-catalyzed coupling reactions of alkyl electrophiles, including unactivated tertiary halides, to generate carbon-boron bonds.

Project description:Through the use of a catalyst formed in situ from NiBr(2)·diglyme and a pybox ligand (both of which are commercially available), we have achieved our first examples of coupling reactions of unactivated tertiary alkyl electrophiles, as well as our first success with nickel-catalyzed couplings that generate bonds other than C-C bonds. Specifically, we have determined that this catalyst accomplishes Miyaura-type borylations of unactivated tertiary, secondary, and primary alkyl halides with diboron reagents to furnish alkylboronates, a family of compounds with substantial (and expanding) utility, under mild conditions; indeed, the umpolung borylation of a tertiary alkyl bromide can be achieved at a temperature as low as -10 °C. The method exhibits good functional-group compatibility and is regiospecific, both of which can be issues with traditional approaches to the synthesis of alkylboronates. In contrast to seemingly related nickel-catalyzed C-C bond-forming processes, tertiary halides are more reactive than secondary or primary halides in this nickel-catalyzed C-B bond-forming reaction; this divergence is particularly noteworthy in view of the likelihood that both transformations follow an inner-sphere electron-transfer pathway for oxidative addition.

| S-EPMC3384763 | biostudies-literature

Nickel-catalyzed reductive thiolation and selenylation of unactivated alkyl bromides.

Project description:Chalcogen-containing compounds have received considerable attention because of their manifold applications in agrochemicals, pharmaceuticals, and material science. While many classical methods have been developed for preparing organic sulfides, most of them exploited the transition-metal-catalyzed cross-couplings of aryl halides or pseudo halides with thiols or disulfides, with harsh reaction conditions usually being required. Herein, we present a user-friendly, nickel-catalyzed reductive thiolation of unactivated primary and secondary alkyl bromides with thiosulfonates as reliable thiolation reagents, which are easily prepared and bench-stable. Furthermore, a series of selenides is also prepared in a similar fashion with selenosulfonates as selenolation reagents. This catalytic method offers a facile synthesis of a wide range of unsymmetrical alkyl-aryl or alkyl-alkyl sulfides and selenides under mild conditions with an excellent tolerance of functional groups. Likewise, the use of sensitive and stoichiometric organometallic reagents can be avoided.

| S-EPMC5993785 | biostudies-other

Nickel-Catalyzed C-Alkylation of Nitroalkanes with Unactivated Alkyl Iodides.

Project description:Enabled by nickel catalysis, a mild and general catalytic method for C-alkylation of nitroalkanes with unactivated alkyl iodides is described. Compatible with primary, secondary, and tertiary alkyl iodides; and tolerant of a wide range of functional groups, this method allows rapid access to diverse nitroalkanes.

| S-EPMC5531607 | biostudies-literature

Nickel-Catalyzed Mizoroki-Heck-Type Reactions of Unactivated Alkyl Bromides.

Project description:The development of a general, nickel-catalyzed alkyl-Mizoroki-Heck reaction of unactivated alkyl bromides is described. The mild reaction proceeds efficiently using a wide range of primary and secondary alkyl bromides, and examples of intermolecular cross-couplings are provided. Reaction alkene regioselectivity is significantly enhanced over prior carbocyclizations using palladium catalysis. Mechanistic investigations are consistent with a direct carbocyclization in contrast to the auto-tandem atom-transfer cyclization and halide elimination previously observed with palladium catalysis.

| S-EPMC6328373 | biostudies-literature

Coupling of Challenging Heteroaryl Halides with Alkyl Halides via Nickel-Catalyzed Cross-Electrophile Coupling.

Project description:Despite their importance, the synthesis of alkylated heterocycles from the cross-coupling of Lewis basic nitrogen heteroaryl halides with alkyl halides remains a challenge. We report here a general solution to this challenge enabled by a new collection of ligands based around 2-pyridyl-N-cyanocarboxamidine and 2-pyridylcarboxamidine cores. Both primary and secondary alkyl halides can be coupled with 2-, 3-, and 4-pyridyl halides as well as other more complex heterocycles in generally good yields (41 examples, 69% ave yield).

| S-EPMC5539790 | biostudies-literature

Mechanism and selectivity in nickel-catalyzed cross-electrophile coupling of aryl halides with alkyl halides.

Project description:The direct cross-coupling of two different electrophiles, such as an aryl halide with an alkyl halide, offers many advantages over conventional cross-coupling methods that require a carbon nucleophile. Despite its promise as a versatile synthetic strategy, a limited understanding of the mechanism and origin of cross selectivity has hindered progress in reaction development and design. Herein, we shed light on the mechanism for the nickel-catalyzed cross-electrophile coupling of aryl halides with alkyl halides and demonstrate that the selectivity arises from an unusual catalytic cycle that combines both polar and radical steps to form the new C-C bond.

| S-EPMC3946589 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data