829-32-3Relevant academic research and scientific papers
Direct Hydrodecarboxylation of Aliphatic Carboxylic Acids: Metal- and Light-Free
Burns, David J.,Lee, Ai-Lan,McLean, Euan B.,Mooney, David T.
supporting information, p. 686 - 691 (2022/01/28)
A mild and inexpensive method for direct hydrodecarboxylation of aliphatic carboxylic acids has been developed. The reaction does not require metals, light, or catalysts, rendering the protocol operationally simple, easy to scale, and more sustainable. Crucially, no additional H atom source is required in most cases, while a broad substrate scope and functional group tolerance are observed.
Dealkenylative Ni-Catalyzed Cross-Coupling Enabled by Tetrazine and Photoexcitation
Cao, Yuhui,Che, Jinteng,Chen, Han,Chen, Si-Cong,Fang, Xianhe,Guo, Yinliang,Guo, Zhixian,Kong, Lingran,Li, Chen,Lu, Jia-Tian,Luo, Tuoping,Zhang, Nan,Zhu, Qi
, p. 14046 - 14052 (2021/09/13)
A new and general method to functionalize the C(sp3)-C(sp2) bond of alkyl and alkene linkages has been developed, leading to the dealkenylative generation of carbon-centered radicals that can be intercepted to undergo Ni-catalyzed C(sp3)-C(sp2) cross-coupling. This one-pot protocol leverages the easily procured alkene feedstocks for organic synthesis with excellent functional group compatibility without the need for a photoredox catalyst.
Catalyst-free Decarboxylation and Decarboxylative Giese Additions of Alkyl Carboxylates through Photoactivation of Electron Donor-Acceptor Complex
Zheng, Chao,Wang, Guang-Zu,Shang, Rui
supporting information, p. 4500 - 4505 (2019/08/26)
We report herein a catalyst-free method to perform decarboxylative conjugated addition and hydrodecarboxylation of aliphatic N-(acyloxy)phthalimides (redox active esters, RAEs) through photoactivation of electron-donor-acceptor (EDA) complex with Hantzsch ester (HE) in N,N-dimethylacetamide (DMA) solution. The reactions present a green method to decarboxylatively construct carbon-carbon bond and to perform hydrodecarboxylation with broad substrate scope and functional group tolerance under mild blue light irradiation condition without recourse of popularly used photoredox catalysts. (Figure presented.).
Modular Functionalization of Arenes in a Triply Selective Sequence: Rapid C(sp2) and C(sp3) Coupling of C?Br, C?OTf, and C?Cl Bonds Enabled by a Single Palladium(I) Dimer
Keaveney, Sinead T.,Kundu, Gourab,Schoenebeck, Franziska
supporting information, p. 12573 - 12577 (2018/09/18)
Full control over multiple competing coupling sites would enable straightforward access to densely functionalized compound libraries. Historically, the site selection in Pd0-catalyzed functionalizations of poly(pseudo)halogenated arenes has been unpredictable, being dependent on the employed catalyst, the reaction conditions, and the substrate itself. Building on our previous report of C?Br-selective functionalization in the presence of C?OTf and C?Cl bonds, we herein complete the sequence and demonstrate the first general arylations and alkylations of C?OTf bonds (in I dimer. This allowed the realization of the first general and triply selective sequential C?C coupling (in 2D and 3D space) of C?Br followed by C?OTf and then C?Cl bonds.
Direct arylation of strong aliphatic C–H bonds
Perry, Ian B.,Brewer, Thomas F.,Sarver, Patrick J.,Schultz, Danielle M.,DiRocco, Daniel A.,MacMillan, David W. C.
, p. 70 - 75 (2018/08/09)
Despite the widespread success of transition-metal-catalysed cross-coupling methodologies, considerable limitations still exist in reactions at sp3-hybridized carbon atoms, with most approaches relying on prefunctionalized alkylmetal or bromide coupling partners1,2. Although the use of native functional groups (for example, carboxylic acids, alkenes and alcohols) has improved the overall efficiency of such transformations by expanding the range of potential feedstocks3–5, the direct functionalization of carbon–hydrogen (C–H) bonds—the most abundant moiety in organic molecules—represents a more ideal approach to molecular construction. In recent years, an impressive range of reactions that form C(sp3)–heteroatom bonds from strong C–H bonds has been reported6,7. Additionally, valuable technologies have been developed for the formation of carbon–carbon bonds from the corresponding C(sp3)–H bonds via substrate-directed transition-metal C–H insertion8, undirected C–H insertion by captodative rhodium carbenoid complexes9, or hydrogen atom transfer from weak, hydridic C–H bonds by electrophilic open-shell species10–14. Despite these advances, a mild and general platform for the coupling of strong, neutral C(sp3)–H bonds with aryl electrophiles has not been realized. Here we describe a protocol for the direct C(sp3) arylation of a diverse set of aliphatic, C–H bond-containing organic frameworks through the combination of light-driven, polyoxometalate-facilitated hydrogen atom transfer and nickel catalysis. This dual-catalytic manifold enables the generation of carbon-centred radicals from strong, neutral C–H bonds, which thereafter act as nucleophiles in nickel-mediated cross-coupling with aryl bromides to afford C(sp3)–C(sp2) cross-coupled products. This technology enables unprecedented, single-step access to a broad array of complex, medicinally relevant molecules directly from natural products and chemical feedstocks through functionalization at sites that are unreactive under traditional methods.
A Versatile Route to Unstable Diazo Compounds via Oxadiazolines and their Use in Aryl–Alkyl Cross-Coupling Reactions
Greb, Andreas,Poh, Jian-Siang,Greed, Stephanie,Battilocchio, Claudio,Pasau, Patrick,Blakemore, David C.,Ley, Steven V.
supporting information, p. 16602 - 16605 (2017/12/13)
Coupling of readily available boronic acids and diazo compounds has emerged recently as a powerful metal-free carbon–carbon bond forming method. However, the difficulty in forming the unstable diazo compound partner in a mild fashion has hitherto limited their general use and the scope of the transformation. Here, we report the application of oxadiazolines as precursors for the generation of an unstable family of diazo compounds using flow UV photolysis and their first use in divergent protodeboronative and oxidative C(sp2)?C(sp3) cross-coupling processes, with excellent functional-group tolerance.
Hydride Reduction by a Sodium Hydride-Iodide Composite
Too, Pei Chui,Chan, Guo Hao,Tnay, Ya Lin,Hirao, Hajime,Chiba, Shunsuke
, p. 3719 - 3723 (2016/03/26)
Sodium hydride (NaH) is widely used as a Br?nsted base in chemical synthesis and reacts with various Br?nsted acids, whereas it rarely behaves as a reducing reagent through delivery of the hydride to polar π electrophiles. This study presents a series of reduction reactions of nitriles, amides, and imines as enabled by NaH in the presence of LiI or NaI. This remarkably simple protocol endows NaH with unprecedented and unique hydride-donor chemical reactivity.
Conversion of Ester Moieties to 4-Bromophenyl Groups via Electrocyclic Reaction of Dibromocyclopropanes
Ueda, Kyosuke,Umihara, Hirotatsu,Yokoshima, Satoshi,Fukuyama, Tohru
supporting information, p. 3191 - 3193 (2015/07/15)
(Chemical Equation Presented) Conversion of ester moieties into 4-bromophenyl groups was effected by means of a four-step protocol: a Grignard reaction of the ester with allylmagnesium halides, a ring-closing metathesis, dibromocyclopropanation, and an electrocyclic reaction of the dibromocyclopropanes.
Nickel-catalyzed selective oxidative radical cross-coupling: An effective strategy for inert Csp3-H functionalization
Liu, Dong,Li, Yuxiu,Liu, Chao,Lei, Aiwen,Qi, Xiaotian,Lan, Yu.
supporting information, p. 998 - 1001 (2015/03/30)
An effective strategy for inert Csp3-H functionalization through nickel-catalyzed selective radical cross-couplings was demonstrated. Density functional theory calculations were conducted and strongly supported the radical cross-coupling pathway assisted by nickel catalyst, which was further confirmed by radical-trapping experiments. Different arylborates including arylboronic acids, arylboronic acid esters and 2,4,6-triarylboroxin were all good coupling partners, generating the corresponding Csp3-H arylation products in good yields.
Iron-catalyzed arene alkylation reactions with unactivated secondary alcohols
Jefferies, Latisha R.,Cook, Silas P.
supporting information, p. 2026 - 2029 (2014/05/06)
A simple, iron-based catalytic system allows for the inter- and intramolecular arylation of unactivated secondary alcohols. This transformation expands the substrate scope beyond the previously required activated alcohols and proceeds under mild reaction conditions, tolerating air and moisture. Furthermore, the use of an enantioenriched secondary alcohol provides an enantioenriched product for the intramolecular reaction, thereby offering a convenient approach to nonracemic products.
