Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Metal-free C(sp³)-H functionalization of sulfonamides via strain-release rearrangement.

ABSTRACT: With the increasing awareness of sustainable chemistry principles, the development of an efficient and mild strategy for C(sp³)-H bond activation of nitrogen-containing compounds without the utilization of any oxidant and metal is still highly desired and challenging. Herein, we present a metal-free reaction system that enables C-H bond functionalization of aliphatic sulfonamides using DABCO as a promoter under mild conditions, affording a series of α,β-unsaturated imines in good yields with high selectivities. This protocol tolerates a broad range of functionalities and can serve as a powerful synthetic tool for the late-stage modification of complex compounds. More importantly, control experiments and detailed DFT calculations suggest that this process involves [2 + 2] cyclization/ring-cleavage reorganization, which opens up a new platform for the establishment of other related reorganization reactions.

SUBMITTER: Hu J

PROVIDER: S-EPMC8179522 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Metal-free C(sp3)-H functionalization of sulfonamides via strain-release rearrangement.

Hu Jiefeng J Yang Xianyu X Shi Shasha S Cheng Bo B Luo Xiaoling X Lan Yu Y Loh Teck-Peng TP

Chemical science 20210122 11

With the increasing awareness of sustainable chemistry principles, the development of an efficient and mild strategy for C(sp3)-H bond activation of nitrogen-containing compounds without the utilization of any oxidant and metal is still highly desired and challenging. Herein, we present a metal-free reaction system that enables C-H bond functionalization of aliphatic sulfonamides using DABCO as a promoter under mild conditions, affording a series of α,β-unsaturated imines in good yiel ...[more]

PMID: 34163674

Similar Datasets

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

Metal-free C(sp(3))-H functionalization: oxidative carbo-oxygenation of ?-diazo carbonyls via radical dediazotization.

Project description:A novel three-component carbo-oxygenation of ?-diazo carbonyls for flexible synthesis of unprecedented ?-aminooxy-?-amino ketones has been established through metal-free C(sp(3))-H functionalization from readily accessible N,N-dimethylanilines and N-hydroxyphthalimide. The reaction pathway involves an in situ-generated phthalimide N-oxyl radical-triggered dediazotization/radical coupling sequence, leading to C-O and C-C bond formation.

| S-EPMC4818971 | biostudies-literature

Metal-free approach for imidazole synthesis via one-pot N-α-C(sp3)-H bond functionalization of benzylamines.

Project description:A metal-free one-pot method is established for the synthesis of tetrasubstituted imidazoles from the reaction of arylmethylamines and 1,2-dicarbonyls/benzoin. The N-α-C(sp3)-H bond functionalization of arylmethylamines using a catalytic amount of AcOH afforded polysubstituted imidazoles under aerobic conditions in significant yields of up to 95%.

| S-EPMC11375450 | biostudies-literature

Metal-free visible-light-promoted C(sp3)-H functionalization of aliphatic cyclic ethers using trace O2.

Project description:Presented is a light-promoted C-C bond forming reaction yielding sulfone and phosphate derivatives at room temperature in the absence of metals or photoredox catalyst. This transformation proceeds in neat conditions through an auto-oxidation mechanism which is maintained through the leaching of trace amounts of O2 as sole green oxidant.

| S-EPMC10181853 | biostudies-literature

Metal-free, photoinduced remote C(sp3)-H borylation.

Project description:Here, we describe a protocol for the metal-free, photo-induced borylation of unactivated C(sp3)-H bonds distal to an O-oxalate hydroxamic ester functionality. The methodology requires only substrate and bis(catecholato)diboron under light irradiation to effect the desired transformation. A range of linear and cyclic tertiary and secondary borylation products are obtained in good yields and high site-selectivity enabling the late-stage C(sp3)-H borylation of natural product derivatives and drug-like compounds.

| S-EPMC10498503 | biostudies-literature

Site-selective amination and/or nitrilation via metal-free C(sp2)-C(sp3) cleavage of benzylic and allylic alcohols.

Project description:Benzylic/allylic alcohols are converted via site-selective C(sp2)-C(sp3) cleavage to value-added nitrogenous motifs, viz., anilines and/or nitriles as well as N-heterocycles, utilizing commercial hydroxylamine-O-sulfonic acid (HOSA) and Et3N in an operationally simple, one-pot process. Notably, cyclic benzylic/allylic alcohols undergo bis-functionalization with attendant increases in architectural complexity and step-economy.

| S-EPMC9067586 | biostudies-literature

Photocatalytic three-component asymmetric sulfonylation via direct C(sp3)-H functionalization.

Project description:The direct and selective C(sp3)-H functionalization of cycloalkanes and alkanes is a highly useful process in organic synthesis owing to the low-cost starting materials, the high step and atom economy. Its application to asymmetric catalysis, however, has been scarcely explored. Herein, we disclose our effort toward this goal by incorporation of dual asymmetric photocatalysis by a chiral nickel catalyst and a commercially available organophotocatalyst with a radical relay strategy through sulfur dioxide insertion. Such design leads to the development of three-component asymmetric sulfonylation involving direct functionalization of cycloalkanes, alkanes, toluene derivatives or ethers. The photochemical reaction of a C(sp3)-H precursor, a SO2 surrogate and a common α,β-unsaturated carbonyl compound proceeds smoothly under mild conditions, delivering a wide range of biologically interesting α-C chiral sulfones with high regio- and enantioselectivity (>50 examples, up to >50:1 rr and 95% ee). This method is applicable to late-stage functionalization of bioactive molecules, and provides an appealing access to enantioenriched compounds starting from the abundant hydrocarbon compounds.

| S-EPMC8062459 | biostudies-literature

Photocatalytic Late-Stage Functionalization of Sulfonamides via Sulfonyl Radical Intermediates.

Project description:A plethora of drug molecules and agrochemicals contain the sulfonamide functional group. However, sulfonamides are seldom viewed as synthetically useful functional groups. To confront this limitation, a late-stage functionalization strategy is described, which allows sulfonamides to be converted to pivotal sulfonyl radical intermediates. This methodology exploits a metal-free photocatalytic approach to access radical chemistry, which is harnessed by combining pharmaceutically relevant sulfonamides with an assortment of alkene fragments. Additionally, the sulfinate anion can be readily obtained, further broadening the options for sulfonamide functionalization. Mechanistic studies suggest that energy-transfer catalysis (EnT) is in operation.

| S-EPMC9127806 | biostudies-literature

A practical preparation of bicyclic boronates via metal-free heteroatom-directed alkenyl sp2-C‒H borylation.

Project description:Bicyclic boronates play critical roles in the discovery of functional materials and antibacterial agents, especially against deadly bacterial pathogens. Their practical and convenient preparation is in high demand but with great challenge. Herein, we report an efficient strategy for the preparation of bicyclic boronates through metal-free heteroatom-directed alkenyl sp2-C‒H borylation. This synthetic approach exhibits good functional group compatibility, and the corresponding boronates bearing halides, aryls, acyclic and cyclic frameworks are obtained with high yields (43 examples, up to 95% yield). Furthermore, a gram-scale experiment is conducted, and downstream transformations of the bicyclic boronates are pursued to afford natural products, drug scaffolds, and chiral hemiboronic acid catalysts.

| S-EPMC10447525 | biostudies-literature

Transition Metal Free sp3-sp3 carbon-carbon coupling between Benzylboronic Esters and Alkyl Bromides.

Project description:A transition metal free coupling reaction of benzylboronic esters and alkyl halides has been developed. Both alkyl bromides and alkyl iodides were found to be competent substrates with the nucleophilic boronate intermediate generated from the combination of benzylboronic ester and an alkyllithium. Good chemoselectivity was observed in substrates with a second electrophile. Both secondary and tertiary benzylboronic esters were effective nucleophiles in the reaction with primary alkyl halides. Mechanistic observations are consistent with a radical mechanism.

| S-EPMC8966628 | biostudies-literature