28271-18-3Relevant academic research and scientific papers
METHODS OF ARENE ALKENYLATION
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Page/Page column 18; 24; 52; 55-56, (2021/11/26)
The present disclosure provides for a rhodium-catalyzed oxidative arene alkenylation from arenes and styrenes to prepare stilbene and stilbene derivatives. For example, the present disclosure provides for method of making arenes or substituted arenes, in particular stilbene and stilbene derivatives, from a reaction of an optionally substituted arene and/or optionally substituted styrene. The reaction includes a Rh catalyst or Rh pre-catalyst material and an oxidant, where the Rh catalyst or Rh catalyst formed Rh pre-catalyst material selectively functionalizes CH bond on the arene compound (e.g., benzene or substituted benzene).
N-Heterocyclic carbene palladium (II)-pyridine (NHC-Pd (II)-Py) complex catalyzed heck reactions
Li, Dan,Tian, Qingqiang,Wang, Xuetong,Wang, Qiang,Wang, Yin,Liao, Siwei,Xu, Ping,Huang, Xin,Yuan, Jianyong
supporting information, p. 2041 - 2052 (2021/05/25)
A mild, efficient, and practical catalytic system for the synthesis of highly privileged stilbene pharmacophores is reported. This system uses N-heterocyclic carbene palladium (II) Pyridine (NHC-Pd (II)-Py) complex to catalyze the formation of carbon-carbon bonds between olefin derivatives and various bromide. This simple, gentle and user-friendly method can offer a variety of stilbene products in excellent yields under solvent-free condition. And its scale-up reaction has excellent yield and this system can be applied to industrial fields. The utility of this method is highlighted by its universality and modular synthesis of a series of bioactive molecules or important medical intermediates.
Synthesis of Stilbenes by Rhodium-Catalyzed Aerobic Alkenylation of Arenes via C-H Activation
Jia, Xiaofan,Frye, Lucas I.,Zhu, Weihao,Gu, Shunyan,Gunnoe, T. Brent
supporting information, p. 10534 - 10543 (2020/06/08)
Arene alkenylation is commonly achieved by late transition metal-mediated C(sp2)-C(sp2) cross-coupling, but this strategy typically requires prefunctionalized substrates (e.g., with halides or pseudohalides) and/or the presence of a directing group on the arene. Transition metal-mediated arene C-H activation and alkenylation offers an alternative method to functionalize arene substrates. Herein, we report a rhodium-catalyzed oxidative arene alkenylation from arenes and styrenes to prepare stilbene and stilbene derivatives. The reaction is successful with several functional groups on both the arene and the olefin including fluoride, chloride, trifluoromethyl, ester, nitro, acetate, cyanide, and ether groups. Reactions of monosubstituted arenes are selective for alkenylation at the meta and para positions, generally with approximately 2:1 selectivity, respectively. Resveratrol and (E)-1,2,3-trimethoxy-5-(4-methoxystyryl)benzene (DMU-212) are synthesized by this single-step approach in high yield. Comparison with palladium catalysis showed that rhodium catalysis is more selective for meta-functionalization for monosubstituted arenes and that the Rh catalysis has better tolerance of halogen groups.
Isolable C@Fe3O4 nanospheres supported cubical Pd nanoparticles as reusable catalysts for Stille and Mizoroki-Heck coupling reactions
Kumar, Basuvaraj Suresh,Anbarasan, Rajagopal,Amali, Arlin Jose,Pitchumani, Kasi
supporting information, p. 3276 - 3282 (2017/07/27)
Cubical Pd nanoparticles incorporated magnetic nanospheres (Pd cNPs/C@Fe3O4) are found to be efficient catalysts for Stille and Mizoroki-Heck coupling reactions. A variety of aryl halides, including chlorides, are converted to biaryls and diphenylethenes with excellent yield and high TON. This immobilization of Pd cNPs on the surface C@Fe3O4 results in structurally stable catalytic sites. The observed enhanced catalytic activity is attributed to the high density of low-coordinated Pd {1?0?0} atoms present at the surface of the Pd cNPs/C@Fe3O4 catalyst. The advantages of the proposed catalytic system are its heterogeneity, high stability, absence of any toxic ligands, gram scale applicability, magnetic separability and consequent reusability.
The aminocyclodextrin/Pd(OAc)2 complex as an efficient catalyst for the Mizoroki-Heck cross-coupling reaction
Kanagaraj, Kuppusamy,Pitchumani, Kasi
supporting information, p. 14425 - 14431 (2013/11/06)
An aminocyclodextrin/Pd(OAc)2 complex is used as an efficient, reusable catalyst in the Mizoroki-Heck reaction of aryl halides/triflates with olefins to give carbon-carbon-coupled products in good to excellent yields. This simple, efficient catalytic system is applicable to a wide range of aryl and heteroaryl halides/triflates and olefins. This environmentally benign procedure is less hazardous, milder, uses a catalytic amount of ligand and Pd(OAc) 2, avoids an inert atmosphere, and catalyst recovery and reusability are achieved. Copyright
Straightforward synthesis of phenanthrenes from styrenes and arenes
Li, Hu,He, Ke-Han,Liu, Jia,Wang, Bi-Qin,Zhao, Ke-Qing,Hu, Ping,Shi, Zhang-Jie
supporting information; experimental part, p. 7028 - 7030 (2012/08/07)
Semi-one-pot synthesis of phenanthrenes from styrenes and arenes was developed through cross-dehydrogenative coupling. A sequence of Heck-type coupling and photo-cyclization were involved and a variety of functionalities were tolerated. This method provides an effective and practical protocol towards the synthesis of substituted phenanthrenes. The Royal Society of Chemistry 2012.
Oxime palladacycle-catalyzed Suzuki-Miyaura alkenylation of aryl, heteroaryl, benzyl, and allyl chlorides under microwave irradiation conditions
Civicos, Jose F.,Alonso, Diego A.,Najera, Carmen
supporting information; experimental part, p. 1683 - 1687 (2011/09/19)
A simple new protocol for the palladium-catalyzed Suzuki-Miyaura cross-coupling of organic chlorides under microwave irradiation is presented. Deactivated aryl and heteroaryl chlorides are efficiently cross-coupled with alkenylboronic acids and potassium alkenyltrifluoroborates using the 4,4′-dichlorobenzophenone oxime-derived palladacycle 1b as precatalyst in 0.1 to 0.5 mol% palladium loading, tris(tert-butyl)phosphonium tetrafluoroborate {[HP(t-Bu)3]BF4} as ligand, tetra-n-butylammonium hydroxide as cocatalyst, and potassium carbonate as base in N,N- dimethylformamide at 130°C under microwave irradiation conditions. Under these conditions, styrenes, stilbenes, and alkenylarenes are obtained in good to high yields, and with high regio- and diastereoselectivities in only 20 min. The reported protocol is also very efficient for the regioselective alkenylation of benzyl and allyl chlorides to afford allylarenes and 1,4-dienes. Copyright
A concise synthesis of substituted stilbenes and styrenes from propargylic phosphonium salts by a cobalt-catalyzed Diels-Alder/wittig olefination reaction sequence
Hilt, Gerhard,Hengst, Christoph
, p. 7337 - 7342 (2008/02/11)
(Chemical Equation Presented) The cobalt(I)-catalyzed Diels-Alder reaction of propargylic phosphonium salts and longer chained alkyne-functionalized phosphonium salts with 1,3-dienes led to dihydroaromatic phosphonium salt intermediates which were directl
Mechanistic criteria for cation radical reactions: Aminium salt-catalyzed cyclopropanation
Yueh, Wang,Bauld, Nathan L.
, p. 5671 - 5676 (2007/10/02)
Mechanistic studies of the cyclopropanation of a series of trans-stilbenes by ethyl diazoacetate catalyzed by two different triarylaminium salts decisively confirm a cation radical mechanism and rule out a hypothetical electrophilic mechanism. The elucidation of key aspects of these cation radical mechanisms, including kinetic vs equilibrium control of ionization and chain vs catalytic mechanisms, has also been achieved for these systems. New mechanistic criteria for the positive identification of cation radical mechanisms are proposed.
Substituent Effect Studies of Aryl-Assisted Solvolyses. II. The Acetolysis of 2-Phenyl-2-(substituted phenyl)ethyl p-Toluenesulfonates
Fujio, Mizue,Maeda, Yasuyuki,Goto, Mutsuo,Saeki, Yoshihiro,Mishima, Masaaki,Tsuno, Yuho
, p. 3021 - 3029 (2007/10/02)
The substituent effect on the acetolysis of 2-phenyl-2-(substituted phenyl)ethyl p-toluenesulfonates had a nonlinear LArSR correlation and was explicable in terms of a competitive aryl-assisted mechanism involving the X-substituted phenyl-assisted (kXM) pathway and the unsubstituted phenyl-assisted (kXN) pathway. By the application of the iterative nonlinear least-squares method based on the LArSR Eq., the substituent effect on the overall kt was dissected into the best-fit kM correlation of ρM=-3.53 with rM=0.60, and the kN correlation of ρN=-0.88 with ?0. The ρM and rM values for the effects of assisting aryl substituents are quite close to those of the 2-methyl-2-phenylpropyl system and the small ρN value with unexalted ?0 constant for the unassisting aryls is compatible to the remote β-aryl effect. The relative rates of competing pathways dissected based on the substituent effect analysis agreed completely with the ratio of respective aryl migration products determined by the 13C-tracer method. Exact rate-product correlation demonstrates that this system involves two discrete aryl-assisted pathways, kXM and kXN, which do not cross over.
