Browse
Submit Data
Databases
API
Help

Dataset Information

21 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Remote Radical Desaturation of Unactivated C-H Bonds in Amides.

ABSTRACT: Desaturation of inert aliphatic C-H bonds in alkanes to form the corresponding alkenes is challenging. In this communication, a new and practical strategy for remote site-selective desaturation of amides via radical chemistry is reported. The readily installed N-allylsulfonylamide moiety serves as an N radical precursor. Intramolecular 1,5-hydrogen atom transfer from an inert C-H bond to the N-radical generates a translocated C-radical which is subsequently oxidized and deprotonated to give the corresponding alkene. The commercially available methanesulfonyl chloride is used as reagent and a Cu/Ag-couple as oxidant. The remote desaturation is realized on different types of unactivated sp³ -C-H bonds. The potential synthetic utility of this method is further demonstrated by the dehydrogenation of natural product derivatives and drugs.

SUBMITTER: Xia Y

PROVIDER: S-EPMC9292639 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Hydroxy-directed fluorination of remote unactivated C(sp3)-H bonds: a new age of diastereoselective radical fluorination.

Project description:We report a photochemically induced, hydroxy-directed fluorination that addresses the prevailing challenge of high diastereoselectivity in this burgeoning field. Numerous simple and complex motifs showcase a spectrum of regio- and stereochemical outcomes based on the configuration of the hydroxy group. Notable examples include a long-sought switch in the selectivity of the refractory sclareolide core, an override of benzylic fluorination, and a rare case of 3,3'-difluorination. Furthermore, calculations illuminate a low barrier transition state for fluorination, supporting our notion that alcohols are engaged in coordinated reagent direction. A hydrogen bonding interaction between the innate hydroxy directing group and fluorine is also highlighted for several substrates with 19F-1H HOESY experiments, calculations, and more.

| S-EPMC9200124 | biostudies-literature

Regioselective Alkylative Cross-Coupling of Remote Unactivated C(sp3)-H Bonds.

Project description:The functionalization of unactivated C(sp3)-H bonds poses a significant challenge due to their ubiquity and relative similarity in most organic frameworks. Herein, we describe the use of a combined photoredox and nickel catalytic system for the regioselective C(sp3)-C(sp3) coupling of unactivated C(sp3)-H bonds and alkyl bromides. Positional selectivity is dictated by a 1,5-hydrogen atom transfer (HAT) reaction by a pendent amide. Interception of this radical by a Ni catalyst allows distal alkylation to occur in good yield and excellent selectivity.

| S-EPMC7097885 | biostudies-literature

Guided desaturation of unactivated aliphatics.

Project description:The excision of hydrogen from an aliphatic carbon chain to produce an isolated olefin (desaturation) without overoxidation is one of the most impressive and powerful biosynthetic transformations for which there are no simple and mild laboratory substitutes. The versatility of olefins and the range of reactions they undergo are unsurpassed in functional group space. Thus, the conversion of a relatively inert aliphatic system into its unsaturated counterpart could open new possibilities in retrosynthesis. In this article, the invention of a directing group to achieve such a transformation under mild, operationally simple, metal-free conditions is outlined. This 'portable desaturase' (Tz(o)Cl) is a bench-stable, commercial entity (Aldrich, catalogue number L510092) that is facile to install on alcohol and amine functionalities to ultimately effect remote desaturation, while leaving behind a synthetically useful tosyl group.

| S-EPMC3405363 | biostudies-literature

Metal-free alcohol-directed regioselective heteroarylation of remote unactivated C(sp3)-H bonds.

Project description:Construction of C-C bonds via alkoxy radical-mediated remote C(sp3)-H functionalization is largely unexplored, as it is a formidable challenge to directly generate alkoxy radicals from alcohols due to the high bond dissociation energy (BDE) of O-H bonds. Disclosed herein is a practical and elusive metal-free alcohol-directed heteroarylation of remote unactivated C(sp3)-H bonds. Phenyliodine bis(trifluoroacetate) (PIFA) is used as the only reagent to enable the coupling of alcohols and heteroaryls. Alkoxy radicals are readily generated from free alcohols under the irradiation of visible light, which trigger the regioselective hydrogen-atom transfer (HAT). A wide range of functional groups are compatible with the mild reaction conditions. Two unactivated C-H bonds are cleaved and one new C-C bond is constructed during the reaction. This protocol provides an efficient strategy for the late-stage functionalization of alcohols and heteroaryls.

| S-EPMC6104081 | biostudies-literature

Transition-Metal- and Light-Free Directed Amination of Remote Unactivated C(sp3)-H Bonds of Alcohols.

Project description:Due to the great value of amino alcohols, new methods for their synthesis are in high demand. Abundant aliphatic alcohols represent the ideal feedstock for the method development toward this important motif. To date, transition-metal-catalyzed approaches for the directed remote amination of alcohols have been well established. Yet, they have certain disadvantages such as the use of expensive catalysts and limited scope. Very recently, transition-metal-free visible-light-induced radical approaches have emerged as new powerful tools for directed remote amination of alcohols. Relying on 1,5-HAT reactivity, these methods are limited to ? - or ?-amination only. Herein, we report a novel transition-metal- and visible-light-free room-temperature radical approach for remote ? -, ?-, and ?-C(sp3)-N bond formation in aliphatic alcohols using mild basic conditions and readily available diazonium salt reagents.

| S-EPMC6873700 | biostudies-literature

Remote Allylation of Unactivated C(sp3)-H Bonds Triggered by Photogenerated Amidyl Radicals.

Project description:The allylation reaction is a highly versatile transformation in chemical synthesis. While many elegant direct C(sp2)-H allylation reactions have been developed, the direct allylation of unactivated C(sp3)-H bonds is underdeveloped. By applying photoredox catalysis and a [1,5]-HAT process, herein we report a direct allylation of unactivated C(sp3)‒H bonds. This photocatalyzed transformation is tolerant of several functional groups in the amide and allylic chloride substrates. Various allyl-substituted amide products were obtained with good yields and high δ-selectivity.

| S-EPMC8186322 | biostudies-literature

Photo-induced copper-catalyzed alkynylation and amination of remote unactivated C(sp3)-H bonds.

Project description:A method for remote radical C-H alkynylation and amination of diverse aliphatic alcohols has been developed. The reaction features a copper nucleophile complex formed in situ as a photocatalyst, which reduces the silicon-tethered aliphatic iodide to an alkyl radical to initiate 1,n-hydrogen atom transfer. Unactivated secondary and tertiary C-H bonds at β, γ, and δ positions can be functionalized in a predictable manner.

| S-EPMC8179574 | biostudies-literature

Practical, metal-free remote heteroarylation of amides via unactivated C(sp3)-H bond functionalization.

Project description:Development of practical methods for the production of multi-functionalized amides is one of the most important topics in both synthetic chemistry and drug discovery. Disclosed herein is a new, efficient, site-selective heteroarylation of amides via C(sp3)-H bond functionalization. Amidyl radicals are directly generated from the amide N-H bonds under mild conditions, which trigger the subsequent 1,5-HAT process. A wide scope of aliphatic amides including carboxamides, sulfonamides, and phosphoramides are readily modified at remote C(sp3)-H bonds by installing diverse heteroaryl groups. Borne out of pragmatic consideration, this protocol can be used for the late-stage functionalization of amides.

| S-EPMC6640195 | biostudies-literature

Functionalization of α-C(sp3 )-H Bonds in Amides Using Radical Translocating Arylating Groups.

Project description:α-C-H arylation of N-alkylamides using 2-iodoarylsulfonyl radical translocating arylating (RTA) groups is reported. The method allows the construction of α-quaternary carbon centers in amides. Various mono- and disubstituted RTA-groups are applied to the arylation of primary, secondary, and tertiary α-C(sp3 )-H-bonds. These radical transformations proceed in good to excellent yields and the cascades comprise a 1,6-hydrogen atom transfer, followed by a 1,4-aryl migration with subsequent SO2 extrusion.

| S-EPMC7898318 | biostudies-literature

Anaerobic functionalization of unactivated C-H bonds.

Project description:The functionalization of alkanes was once thought to lie strictly within the domain of enzymes that activate dioxygen in order to generate an oxidant with suitable potency to cleave inert C-H bonds. The emergence of the radical SAM superfamily of enzymes-those which use S-adenosyl-l-methionine as a precursor to a 5'-deoxyadenosyl 5'-radical-has kindled a renaissance in the study of radical-dependent enzymatic reactions, and is ushering in a wealth of new and intriguing chemistry that remains to be elucidated. This review will focus on a special subclass of radical SAM enzymes that functionalize inert C-H bonds, highlighting the functional groups and the chemistry that leads to their insertion. Within this class are first, enzymes that catalyze sulfur insertion, the prototype of which is biotin synthase; second, enzymes that catalyze P-methylation or C-methylation, such as P-methylase or Fom3; third, enzymes that catalyze oxygen insertion, such as the anaerobic magnesium protoporphyrin-IX oxidative cyclase (BchE); and fourth, enzymes that functionalize n-hexane or other alkanes as the first step in the metabolism of these inert compounds by certain bacteria. In addition to surveying reactions that have been studied at various levels of detail, this review will speculate on the mechanisms of other types of reactions that this chemistry lends itself to.

| S-EPMC2762545 | 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