15324-90-0Relevant academic research and scientific papers
Volatile non-terpenoid hydrocarbons from Ligusticum grayi roots
Cool, Laurence G.,Takeoka, Gary R.,Vermillion, Karl E.
, p. 158 - 160 (2011)
The root essential oil of Ligusticum grayi Coult. & Rose (Apiaceae) was found to contain three volatile non-terpenoid hydrocarbons: the known C 11 compound viridene, whose structure is hereby corrected to 1-[(2Z)-pent-2-en-1-yl]cyclohexa-1,3-diene; and the heretofore unreported C 10 compounds 1-[(2Z)-but-2-en-1-yl]cyclohexa-1,3-diene (norviridene), and (Z)-but-2-en-1-ylbenzene (ar-norviridene). These compounds are structurally similar to the 3-alkylphthalides that are widespread in the Apiaceae and, like the latter, probably arise from polyketide precursors.
Regioselective Allylation of a Grignard Reagent Catalysed by Phosphine-Nickel and -Palladium Complexes
Hayashi, Tamio,Konishi, Mitsuo,Yokota, Kan-ichi,Kumada, Makoto
, p. 313 - 314 (1981)
Nickel and palladium complexes of the 1,1'-bis(diphenylphosphino)ferrocene ligand effectively catalysed the regioselective cross-coupling of allylic ethers with phenylmagnesium bromide; use of the nickel catalyst leads to carbon-carbon bond formation giving the terminal alkene while the palladium catalyst gives the non-terminal alkene.
Double-Bond Isomerization: Highly Reactive Nickel Catalyst Applied in the Synthesis of the Pheromone (9 Z,12 Z)-Tetradeca-9,12-dienyl Acetate
Weber, Felicia,Schmidt, Anastasia,R?se, Philipp,Fischer, Michel,Burghaus, Olaf,Hilt, Gerhard
, p. 2952 - 2955 (2015)
A highly reactive nickel catalyst comprising NiCl2(dppp) or NiCl2(dppe) with zinc powder, ZnI2 and Ph2PH, was applied in the isomerization of terminal alkenes to Z-2-alkenes. The double-bond geometry of the 2-alkene can be controlled via the reaction temperature to yield the 2-Z-alkenes in excellent yields and high Z-selectivities. The formation of other constitutional isomers, such as 3-alkenes, is suppressed on the basis of the proposed mechanism via a 1,2-hydride shift from the metal to the Ph2P ligand. The nickel-catalyzed isomerization reaction was then applied in the synthesis of (9Z,12Z)-tetradeca-9,12-dienyl acetate, a pheromone with a 2Z,5Z-diene subunit.
Modular Ni(0)/Silane Catalytic System for the Isomerization of Alkenes
Chang, Alison Sy-Min,Cook, Amanda K.,Kawamura, Kiana E.,Martin, Daryl J.,Morris, Parker T.,Smith, Haley M.
, p. 486 - 496 (2022/03/02)
Alkenes are used ubiquitously as starting materials and synthetic targets in all areas of chemistry. Controlling their geometry and position along a chain is vital to their reactivity and properties yet remains challenging. Alkene isomerization is an atom-economical process to synthesize targeted alkenes, and selectivity can be controlled using transition metal catalysts. The development of mild, selective isomerization reactivity has enabled efficient tandem catalytic systems for the remote functionalization of alkenes, a process in which a starting alkene is isomerized to a new position prior to the functionalization step. The key challenges in developing isomerization catalysts for remote functionalization applications are (i) a lack of modularity in the catalyst structure and (ii) the requirement of nonmodular and/or harsh additives during catalyst activation. We address both challenges with a modular (NHC)Ni(0)/silane catalytic system (NHC, N-heterocyclic carbene), demonstrating the use of triaryl silanes and readily accessible (NHC)Ni(0) complexes to form the proposed active (NHC)(silyl)Ni-H species in situ. We show that modification of the steric and electronic nature of the catalyst via modification of the ancillary ligand and silane partner, respectively, is easily achieved, creating a uniquely versatile catalytic system that is effective for the formation of internal alkenes with high yield and selectivity for the E-alkene. The use of silanes as mild activators enables isomerization of substrates with a variety of functional groups, including acid-labile groups. The broad substrate scope, enabled by catalyst design, makes this catalytic system a strong candidate for use in tandem catalytic applications. Preliminary mechanistic studies support a Ni-H insertion/elimination pathway.
Selecting double bond positions with a single cation-responsive iridium olefin isomerization catalyst
Camp, Andrew M.,Kita, Matthew R.,Blackburn, P. Thomas,Dodge, Henry M.,Chen, Chun-Hsing,Miller, Alexander J.M.
supporting information, p. 2792 - 2800 (2021/03/01)
The catalytic transposition of double bonds holds promise as an ideal route to alkenes of value as fragrances, commodity chemicals, and pharmaceuticals; yet, selective access to specific isomers is a challenge, normally requiring independent development of different catalysts for different products. In this work, a single cation-responsive iridium catalyst selectively produces either of two different internal alkene isomers. In the absence of salts, a single positional isomerization of 1-butene derivatives furnishes 2-alkenes with exceptional regioselectivity and stereoselectivity. The same catalyst, in the presence of Na+, mediates two positional isomerizations to produce 3-alkenes. The synthesis of new iridium pincer-crown ether catalysts based on an aza-18-crown-6 ether proved instrumental in achieving cation-controlled selectivity. Experimental and computational studies guided the development of a mechanistic model that explains the observed selectivity for various functionalized 1-butenes, providing insight into strategies for catalyst development based on noncovalent modifications.
Regiocontrolled Reductive Vinylation of Aliphatic 1,3-Dienes with Vinyl Triflates by Nickel Catalysis
Pang, Xiaobo,Zhao, Zhen-Zhen,Wei, Xiao-Xue,Qi, Liangliang,Xu, Guang-Li,Duan, Jicheng,Liu, Xue-Yuan,Shu, Xing-Zhong
supporting information, p. 4536 - 4542 (2021/04/07)
The regiocontrolled functionalization of 1,3-dienes has become a powerful tool for divergent synthesis, yet it remains a long-standing challenge for aliphatic substrates. Herein, we report a reductive approach for a branch-selective 1,2-hydrovinylation of aliphatic 1,3-dienes with R-X electrophiles, which represents a new selectivity pattern for diene functionalization. Simple butadiene, aromatic 1,3-dienes, and highly conjugated polyene were also tolerated. The combination of Ni(0) and the phosphine-nitrile ligand generally resulted in >20:1 regioselectivity with the retention of the geometry of the C3-C4 double bonds. This reaction proceeds with a broad substrate scope, and it allows for the conjugation of two biologically active units to form more complex polyene molecules, such as tetraene and pentaene as well as heptaene.
Tandem Olefin Isomerization/Cyclization Catalyzed by Complex Nickel Hydride and Br?nsted Acid
Kathe, Prasad M.,Caciuleanu, Alexandru,Berkefeld, Andreas,Fleischer, Ivana
, p. 15183 - 15196 (2020/11/30)
We disclose a nickel/Br?nsted acid-catalyzed tandem process consisting of double bond isomerization of allyl ethers and amines and subsequent intramolecular reaction with nucleophiles. The process is accomplished by [(Me3P)4NiH]N(SO2CF3)2 in the presence of triflic acid. The methodology provides rapid access to tetrahydropyran-fused indoles and other oxacyclic scaffolds under very low catalyst loadings.
Selective α,δ-hydrocarboxylation of conjugated dienes utilizing CO2and electrosynthesis
Buckley, Benjamin R.,Elmorsy, Saad S.,Malkov, Andrei V.,Mashaly, Mohammad A.,Said, Samy B.,Sheta, Ahmed M.
, p. 9109 - 9114 (2020/09/17)
To date the majority of diene carboxylation processes afford the α,δ-dicarboxylated product, the selective mono-carboxylation of dienes is a significant challenge and the major product reported under transition metal catalysis arises from carboxylation at the α-carbon. Herein we report a new electrosynthetic approach, that does not rely on a sacrificial electrode, the reported method allows unprecedented direct access to carboxylic acids derived from dienes at the δ-position. In addition, the α,δ-dicarboxylic acid or the α,δ-reduced alkene can be easily accessed by simple modification of the reaction conditions. This journal is
Controllable Isomerization of Alkenes by Dual Visible-Light-Cobalt Catalysis
Meng, Qing-Yuan,Schirmer, Tobias E.,Katou, Kousuke,K?nig, Burkhard
supporting information, p. 5723 - 5728 (2019/04/03)
We report herein that thermodynamic and kinetic isomerization of alkenes can be accomplished by the combination of visible light with Co catalysis. Utilizing Xantphos as the ligand, the most stable isomers are obtained, while isomerizing terminal alkenes over one position can be selectively controlled by using DPEphos as the ligand. The presence of the donor–acceptor dye 4CzIPN accelerates the reaction further. Transformation of exocyclic alkenes into the corresponding endocyclic products could be efficiently realized by using 4CzIPN and Co(acac)2 in the absence of any additional ligands. Spectroscopic and spectroelectrochemical investigations indicate CoI being involved in the generation of a Co hydride, which subsequently adds to alkenes initiating the isomerization.
Asymmetric Synthesis of 1-Benzazepine Derivatives via Copper-Catalyzed Intramolecular Reductive Cyclization
Li, Dingxi,Park, Yeji,Yoon, Woojin,Yun, Hoseop,Yun, Jaesook
supporting information, p. 9699 - 9703 (2019/11/19)
An asymmetric construction of enantioenriched 2,3-substituted-1-benzazepine derivatives containing a cyclic tertiary amine moiety was developed by copper-catalyzed reductive intramolecular cyclization of (E)-dienyl arenes with a tethered ketimine. This pr
