37909-95-8Relevant academic research and scientific papers
C-F activation for C(sp2)-C(sp3) cross-coupling by a secondary phosphine oxide (SPO)-nickel complex
Müller, Valentin,Ghorai, Debasish,Capdevila, Lorena,Messinis, Antonis M.,Ribas, Xavi,Ackermann, Lutz
supporting information, p. 7034 - 7040 (2020/09/15)
A secondary phosphine oxide (SPO)-nickel catalyst allowed the activation of otherwise inert C-F bonds of unactivated arenes in terms of challenging couplings with primary and secondary alkyl Grignard reagents. The C-F activation is characterized by mild reaction conditions and high levels of branched selectivity. Electron-rich and electron-deficient arenes were suitable electrophiles for this transformation. In addition, this strategy also proved suitable to heterocycles and for the activation of C-O bonds under slightly modified conditions.
Purposeful regioselectivity control of the Birch reductive alkylation of biphenyl-4-carbonitrile
Fedyushin, Pavel A.,Peshkov, Roman Yu.,Panteleeva, Elena V.,Tretyakov, Evgeny V.,Beregovaya, Irina V.,Gatilov, Yuri V.,Shteingarts, Vitalij D.
, p. 842 - 851 (2018/01/19)
Birch's reductive alkylation of biphenyl-4-carbonitrile (1) provides alkylated 1,4-dihydroderivatives of various structural types: 4-alkyl-4-phenylcyclohexa-2,5-dienone, 1,4-dialkyl-4-phenylcyclohexa-2,5-dienecarbonitrile (with the same or different alkyl fragments), and 4-(1-alkylcyclohexa-2,5-dienyl)benzonitrile. Each of these products become dominant depending on the nature of long-living anionic form generated from 1, namely, the stable product of two-electrons reduction – dianion (12?); 1-alkyl-4-cyano-1-phenylcyclohexa-2,5-dien-4-yl anion (1-Alk1–), originated due to the alkylation of dianion 12? at the position 1 of biphenyl moiety; or 1-(4-cyanophenyl)cyclohexa-2,5-dien-1-yl anion (1-H4’–), being the product of dianion 12? protonation at position 4′ by protonating reagent (MeOH or NH4Cl). The orientation of alkyl fragment incorporation into biphenyl-4-carbonitrile scaffold is in agreement with calculated electronic structure of the anionic species under investigation. The dominating type of their reactivity towards alkyl halides proved to be nucleophilic (SN2 mechanism).
Highly regio- and stereoselective palladium-catalyzed allene bifunctionalization cascade via π-allyl intermediate
Bai, Tao,Yang, Yanhui,Janes, Trevor,Song, Datong,Guo, Zhiqiang
supporting information, p. 5784 - 5793 (2017/09/05)
We report a palladium-catalyzed allene bifunctionalization reaction that forms C–C and either C–O or C–N bonds in one pot with excellent regio- and stereoselectivity. Carboxylic acids, amides, and hydroxide are all suitable nucleophiles. Organoboronic acid acts as hydroxide transfer reagent. An intermediate π-allyl palladium complex was isolated, which yields improved catalytic performance as well as evidence of the origin of stereoselectivity. A derivatization study emphasizes the utility of the functionalized allylic products.
Nickel-Catalyzed Cross-Coupling of Organolithium Reagents with (Hetero)Aryl Electrophiles
Heijnen, Dorus,Gualtierotti, Jean-Baptiste,Hornillos, Valentín,Feringa, Ben L.
supporting information, p. 3991 - 3995 (2016/03/16)
Nickel-catalyzed selective cross-coupling of aromatic electrophiles (bromides, chlorides, fluorides and methyl ethers) with organolithium reagents is presented. The use of a commercially available nickel N-heterocyclic carbene (NHC) complex allows the reaction with a variety of (hetero)aryllithium compounds, including those prepared via metal-halogen exchange or direct metallation, whereas a commercially available electron-rich nickel-bisphosphine complex smoothly converts alkyllithium species into the corresponding coupled product. These reactions proceed rapidly (1 h) under mild conditions (room temperature) while avoiding the undesired formation of reduced or homocoupled products. Nickel-catalyzed cross-coupling of aromatic electrophiles with organolithium reagents is presented. The use of a commercially available nickel N-heterocyclic carbene complex allows reaction with a variety of (hetero)aryllithium compounds, whereas a commercially available electron-rich nickel bisphosphine complex smoothly converts alkyllithium species into the corresponding coupled product.
Thermal transformations of 4-tert-butylbiphenyl
Repkin,Nesterova,Nesterov,Golovin
experimental part, p. 149 - 153 (2011/08/05)
The thermal stability of 4-tert-butylbiphenyl was studied in the range of 703-763 K. The competition of the cracking and isomerization reactions of alkyl substituents on the aromatic ring of the reactant and its products has been revealed. The kinetic characteristics of the complex of transformations occurring in the system have been determined. Recommendations are provided regarding the conditions for the determination of the critical parameters of 4-tert-butylbiphenyl and for the processing and use of compounds with a tert-butyl moiety in the molecule.
Pd/P(t-Bu)3: A mild and general catalyst for stille reactions of aryl chlorides and aryl bromides
Littke, Adam F.,Schwarz, Lothar,Fu, Gregory C.
, p. 6343 - 6348 (2007/10/03)
Pd/P(t-Bu)3 serves as an unusually reactive catalyst for Stille reactions of aryl chlorides and bromides, providing solutions to a number of long-standing challenges. An unprecedented array of aryl chlorides can be cross-coupled with a range of organotin reagents, including SnBu4. Very hindered biaryls (e.g., tetra-ortho-substituted) can be synthesized, and aryl chlorides can be coupled in the presence of aryl triflates. The method is user-friendly, since a commercially available complex, Pd(P(t-Bu)3)2, is effective. Pd/P(t-Bu)3 also functions as an active catalyst for Stille reactions of aryl bromides, furnishing the first general method for room-temperature cross-couplings.
