7642-05-9Relevant academic research and scientific papers
Ni-Catalyzed Regioselective Hydroarylation of 1-Aryl-1,3-Butadienes with Aryl Halides
Wang, Chengdong,Guo, Yingjie,Wang, Xiaoming,Wang, Zheng,Ding, Kuiling
supporting information, p. 15903 - 15907 (2021/10/07)
An efficient nickel-catalyzed regioselective hydroarylation of 1,3-dienes with aryl halides and a silane has been developed, affording a range of allylic arenes in good to excellent yields under mild conditions. This method exhibits broad substrate scope,
Iron-Catalyzed Tunable and Site-Selective Olefin Transposition
Yu, Xiaolong,Zhao, Haonan,Li, Ping,Koh, Ming Joo
supporting information, p. 18223 - 18230 (2020/12/04)
The catalytic isomerization of C-C double bonds is an indispensable chemical transformation used to deliver higher-value analogues and has important utility in the chemical industry. Notwithstanding the advances reported in this field, there is compelling demand for a general catalytic solution that enables precise control of the C═C bond migration position, in both cyclic and acyclic systems, to furnish disubstituted and trisubstituted alkenes. Here, we show that catalytic amounts of an appropriate earth-abundant iron-based complex, a base and a boryl compound, promote efficient and controllable alkene transposition. Mechanistic investigations reveal that these processes likely involve in situ formation of an iron-hydride species which promotes olefin isomerization through sequential olefin insertion/β-hydride elimination. Through this strategy, regiodivergent access to different products from one substrate can be facilitated, isomeric olefin mixtures commonly found in petroleum-derived feedstock can be transformed to a single alkene product, and unsaturated moieties embedded within linear and heterocyclic biologically active entities can be obtained.
Palladium-Catalyzed Regio- A nd Enantioselective Hydrosulfonylation of 1,3-Dienes with Sulfinic Acids: Scope, Mechanism, and Origin of Selectivity
Dong, Dongfang,Zhang, Qinglong,Zi, Weiwei
supporting information, p. 15860 - 15869 (2020/10/18)
Chiral sulfones are important structural motifs in organic synthesis because of their widespread use in pharmaceutical chemistry. In particular, chiral allylic sulfones have drawn particular interest because of their synthetic utility. However, enantioselective synthesis of 1,3-disubstituted unsymmetrical chiral allylic sulfones remains a challenge. In this article, we report a protocol for (R)-DTBM-Segphos/Pd-catalyzed regio- A nd enantioselective hydrosulfonylation of 1,3-dienes with sulfinic acids, which provides atom- A nd step-economical access to 1,3-disubstituted chiral allylic sulfones. The reaction occurs under mild conditions and has a broad substrate scope. Combined experimental and computational studies suggest that the reaction is initiated by a ligand-to-ligand hydrogen transfer followed by a C-S bond reductive elimination via a six-membered transition state. Steric repulsion between the olefinic C-H of the substrate and the tert-butyl group of (R)-DTBM-Segphos was found to be a key factor in the enantiocontrol.
Mild Isomerization of Conjugated Dienes Using Co-Mediated Hydrogen Atom Transfer
Delgado, Kyle R.,Youmans, Dustin D.,Diver, Steven T.
supporting information, p. 750 - 754 (2020/01/31)
A mild and high yielding rearrangement of 1,3-disubstituted-1,3-dienes to 1,1,4-trisubstituted-1,3-dienes using a cobaloxime catalyst and a silane cocatalyst is reported. Chiral centers near the conjugated diene were not racemized. Deuterium labeling studies are consistent with a hydrogen atom transfer mechanism, and radical intermediates were found to be accessible due to the observed ring opening of a cyclopropane ring.
Transition-Metal-Free Allylic Borylation of 1,3-Dienes
Maza, Ricardo J.,Davenport, Elliot,Miralles, Núria,Carbó, Jorge J.,Fernández, Elena
supporting information, p. 2251 - 2255 (2019/04/10)
This work explains the reactivity of diboron reagents with 1,3-dienes in a transition-metal-free context. The sole addition of Na2CO3 (30 mol %) to bis(pinacolato)diboron in MeOH allows the 1,4-hydroboration of cyclic and noncyclic 1,3-dienes. The electronic influence on the substrate guarantees the conjugated 1,4-hydroboration versus 1,2-diboration. DFT calculations show that the distribution of charge in the allylic anion intermediate governs the selectivity toward 1,4-hydroboration, while the favored trans configuration in diene reagents determines the preference for the E allyl boronate products.
Development and Mechanistic Investigations of Enantioselective Pd-Catalyzed Intermolecular Hydroaminations of Internal Dienes
Park, Sangjune,Malcolmson, Steven J.
, p. 8468 - 8476 (2018/09/18)
We report the development of highly enantio- and regioselective Pd-catalyzed intermolecular hydroaminations of challenging 1,4-disubstituted acyclic dienes. Several aryl/alkyl-disubstituted dienes and a sterically differentiated alkyl/alkyl-disubstituted diene undergo coupling with a variety of secondary aliphatic amines, indoline, and primary anilines to generate allylic amines with myriad α-alkyl groups in up to 78% yield, >98:2 rr, and 98.5:1.5 er. A number of experiments, including deuterium labeling and transamination studies, shed light on mechanistic details of the reaction, such as the reversibility of individual steps of the proposed catalytic cycle and of the reaction as a whole.
Transition-metal-free synthesis of vicinal triborated compounds and selective functionalisation of the internal C-B bond
Davenport, Elliot,Fernandez, Elena
supporting information, p. 10104 - 10107 (2018/09/18)
1,2,3-Triborated compounds can be prepared by simple nucleophilic borylation of 1,3-dienes, without the assistance of metal catalysts. Selective functionalisation of the internal C-B bond of the 1,2,3-triborated compounds, through cross-coupling with aryl
Ligand-Free Iron-Catalyzed Carbon(sp2)-Carbon(sp2) Cross-Coupling of Alkenyllithium with Vinyl Halides
Liu, Qiang,Wang, Zhi-Yong,Peng, Xiao-Shui,Wong, Henry N. C.
supporting information, p. 6325 - 6333 (2018/06/01)
An efficient ligand-free iron-catalyzed cross-coupling reaction involving alkenyllithium and vinyl iodides was developed to form diene species in moderate to good yields. This new iron-catalyzed cross-coupling reaction provides a mild, inexpensive, and environmentally friendly avenue toward synthesis of diversified diene derivatives.
Flow Dehydration and Hydrogenation of Allylic Alcohols: Application to the Waste-Free Synthesis of Pristane
Furuta, Akihiro,Hirobe, Yuki,Fukuyama, Takahide,Ryu, Ilhyong,Manabe, Yoshiyuki,Fukase, Koichi
supporting information, p. 1365 - 1368 (2017/03/23)
Hydroxy-substituted sulfonic acid functionalized silica (HO-SAS) in combination with THF containing a small amount of water as a solvent proved to be a reliable system for the dehydration of allylic alcohols. This process generally caused dehydration within 1 min through a column reactor charged with HO-SAS. The flow dehydration was sequenced by flow hydrogenation, which resulted in the synthesis of pristane. A scalable flow synthesis of pristane was successfully performed and afforded 10 g of pristane after an operation of 2 h. We also performed dehydration and hydrogenation by using a mixed column of HO-SAS and 10 % Pd/C.
Chiral Pincer Carbodicarbene Ligands for Enantioselective Rhodium-Catalyzed Hydroarylation of Terminal and Internal 1,3-Dienes with Indoles
Marcum, Justin S.,Roberts, Courtney C.,Manan, Rajith S.,Cervarich, Tia N.,Meek, Simon J.
supporting information, p. 15580 - 15583 (2017/11/14)
Catalytic enantioselective addition of N-heteroarenes to terminal and internal 1,3-dienes is reported. Reactions are promoted by 5 mol % of Rh catalyst supported by a new chiral pincer carbodicarbene ligand that delivers allylic substituted arenes in up to 95% yield and up to 98:2 er. Mechanistic and X-ray evidence is presented that supports that the reaction proceeds via a Rh(III)-η3-allyl.
