19819-29-5

Upstream product

• 163813-84-1 Formic acid 1-(3,4-dimethoxy-phenyl)-4-iodo-butyl ester 
• 120-14-9 3,4-dimethoxy-benzaldehyde 
• 21852-32-4 4-bromomethyl-1,2-dimethoxybenzene 
• 83318-94-9 (3,4-dimethoxybenzyl)(phenyl)sulfane 
• 109-99-9 tetrahydrofuran 
• 2859-78-1 4-Bromoveratrole 
• 89980-69-8 3,4-dimethoxyphenylmagnesium bromide 
• 120346-80-7 tetrahydro-2-(phenylsulphonyl)furan 

Relevant academic research and scientific papers

Site- And enantiodifferentiating C(sp3)-H oxidation enables asymmetric access to structurally and stereochemically diverse saturated cyclic ethers

A manganese-catalyzed site- and enantiodifferentiating oxidation of C(sp3)-H bonds in saturated cyclic ethers has been described. The mild and practical method is applicable to a range of tetrahydrofurans, tetrahydropyrans, and medium-sized cyclic ethers with multiple stereocenters and diverse substituent patterns in high efficiency with extremely efficient site- and enantiodiscrimination. Late-stage application in complex biological active molecules was further demonstrated. Mechanistic studies by combined experiments and computations elucidated the reaction mechanism and origins of stereoselectivity. The ability to employ ether substrates as the limiting reagent, together with a broad substrate scope, and a high level of chiral recognition, represent a valuable demonstration of the utility of asymmetric C(sp3)-H oxidation in complex molecule synthesis.

PHOTOCATALYST SYSTEM AND USE THEREOF IN A PHOTOCATALYTIC PROCESS

Photocatalyst system and use thereof in a photochemical process The invention relates to a photocatalyst system comprising, in the absence of a further photosensitizer other than the compound of formula (III) or a mixture thereof: (i) a nickel(II) salt, (

Sp3 C-H Arylation and Alkylation Enabled by the Synergy of Triplet Excited Ketones and Nickel Catalysts

Triplet ketone sensitizers are of central importance within the realm of photochemical transformations. Although the radical-type character of triplet excited states of diaryl ketones suggests the viability for triggering hydrogen-atom transfer (HAT) and single-electron transfer (SET) processes, among others, their use as multifaceted catalysts in C-C bond-formation via sp3 C-H functionalization of alkane feedstocks still remains rather unexplored. Herein, we unlock a modular photochemical platform for forging C(sp3)-C(sp2) and C(sp3)-C(sp3) linkages from abundant alkane sp3 C-H bonds as functional handles using the synergy between nickel catalysts and simple, cheap and modular diaryl ketones. This method is distinguished by its wide scope that is obtained from cheap catalysts and starting precursors, thus complementing existing inner-sphere C-H functionalization protocols or recent photoredox scenarios based on iridium polypyridyl complexes. Additionally, such a platform provides a new strategy for streamlining the synthesis of complex molecules with high levels of predictable site-selectivity and preparative utility. Mechanistic experiments suggest that sp3 C-H abstraction occurs via HAT from the ketone triplet excited state. We believe this study will contribute to a more systematic utilization of triplet excited ketones as catalysts in metallaphotoredox scenarios.

Visible-Light-Induced Cyclization of Electron-Enriched Phenyl Benzyl Sulfides: Synthesis of Tetrahydrofurans and Tetrahydropyrans

A new approach to the preparation of tetrahydrofurans and tetrahydropyrans through a photoredox catalytic process is described. The introduction of a phenylsulfanyl auxiliary group permits the substrates to be readily oxidized to form cationic intermediates for sequential intramolecular cyclization. The method features mild reaction conditions and operational simplicity.

Photoinduced molecular transformations. 157. A new stereo- and regioselective synthesis of 2,6-diaryl-3,7-dioxabicyclo[3.3.0]octane lignans involving a β-scission of alkoxyl radicals as the key step. New total syntheses of (±)-sesamin, (±)-eudesmin, and (±)-yangambin

New total syntheses of naturally occurring 2,6-diaryl-3,7-dioxabicyclo[3.3.0]octane lignans, (±)-sesamin and (±)-eudesmin, and the first total synthesis of (±)-yangambin were achieved according to a general method devised by Suginome and colleagues for replacing the carbonyl group of the cyclopentanone ring with an oxygen atom to give a corresponding tetrahydrofuran ring involving a regioselective β-scission of alkoxyl radicals; arylation of dimethyl, diallyl, or dibenzyl 3,7-dioxobicyclo[3.3.0]octane-2,6-dicarbonate (18 and 19a,b) with aryllead triacetate 9a-c, followed by dealkoxycarbonylation of the resulting arylated product 20a-f, gave 2,6-diaryl-3,7-dioxobicyclo[3.3.0]octane 21a-c. A regioselective Baeyer-Villiger oxidation of 21a-c with m-CPBA-NaHCO3 or -K2CO3 gave the corresponding δ-lactone 22a-c, which was reduced with DIBAL to give the corresponding lactol 23a-c. The irradiation of a solution of the hypoiodite of 23a-c, generated in situ with mercury(II) oxide-iodine, in benzene with Pyrex-filtered light resulted in a regioselective β-scission of the corresponding alkoxyl radical to give iodo formate 24a-c. Heating 24a-c in MeOH with NaBH4 gave (±)-sesamin (25a), (±)-eudesmin (25b), or (±)-yangambin (25c).