7302-01-4Relevant academic research and scientific papers
Nickel-Catalyzed Arylation of C(sp3)-O Bonds in Allylic Alkyl Ethers with Organoboron Compounds
Li, Xiaowei,Li, Yuxiu,Zhang, Zhong,Shi, Xiaolin,Liu, Ruihua,Wang, Zemin,Li, Xiangqian,Shi, Dayong
, p. 6612 - 6616 (2021/09/02)
A nickel-catalyzed cross-coupling of allylic alkyl ethers with organoboron compounds through the cleavage of the inert C(sp3)-O(alkyl) bonds is described. Several types of allylic alkyl ethers can be coupled with various boronic acids or their derivatives to give the corresponding products in good to excellent yields with wide functional group tolerance and excellent regioselectivity. The gram-scale reaction and late-stage modification of biologically active compounds further prove the practicality of this synthetic method.
Enantioselective Hydroalkenylation of Olefins with Enol Sulfonates Enabled by Dual Copper Hydride and Palladium Catalysis
Schuppe, Alexander W.,Knippel, James Levi,Borrajo-Calleja, Gustavo M.,Buchwald, Stephen L.
supporting information, p. 5330 - 5335 (2021/05/04)
The catalytic enantioselective synthesis of α-chiral olefins represents a valuable strategy for rapid generation of structural diversity in divergent syntheses of complex targets. Herein, we report a protocol for the dual CuH- and Pd-catalyzed asymmetric Markovnikov hydroalkenylation of vinyl arenes and the anti-Markovnikov hydroalkenylation of unactivated olefins, in which readily available enol triflates can be utilized as alkenyl coupling partners. This method allowed for the synthesis of diverse α-chiral olefins, including tri- and tetrasubstituted olefin products, which are challenging to prepare by existing approaches.
Preparation and application of triphenylphosphine allyl palladium halide compound and derivative thereof
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Paragraph 0183-0188, (2020/05/30)
The invention discloses a synthesis method of a triphenylphosphine allyl palladium halide compound and a derivative thereof. The synthesis method comprises the step of carrying out one-step reaction on a mixture containing a palladium salt, a halogenated allyl compound and a trisubstituted phosphine compound to obtain the triphenylphosphine allyl palladium halide compound and the derivative thereof. The method is low in cost, high in efficiency, easy to operate and high in safety. The prepared triphenylphosphine allyl palladium halide compound and the derivative thereof can be widely applied as catalysts to catalytic cross coupling or homogeneous coupling reactions of various types of organic substrates so as to prepare various organic reaction intermediates.
In Situ Ring-Closing Strategy for Direct Synthesis of N-Heterocyclic Carbene Nickel Complexes and Their Application in Coupling of Allylic Alcohols with Aryl Boronic Acids
Wang, Yu-Bin,Liu, Bin-Yuan,Bu, Qingqing,Dai, Bin,Liu, Ning
, p. 2930 - 2940 (2020/06/17)
A in situ ring-closing strategy was developed for the synthesis of N-heterocyclic carbene nickel complexes. The process was carried out in air, and did not require solvent purification. The resulting nickel complexes were investigated as catalysts for the coupling of allylic alcohols with aryl boronic acids. A wide range of allylic substrates and aryl acids proved to be applicable to this catalytic system. Control experiments suggest that the Ni(0) may be the true active species in the coupling reactions. (Figure presented.).
Nickel-Catalyzed Hydroarylation of in Situ Generated 1,3-Dienes with Arylboronic Acids Using a Secondary Homoallyl Carbonate as a Surrogate for the 1,3-Diene and Hydride Source
Hamaguchi, Takashi,Kawatsura, Motoi,Takahashi, Yoshiyuki,Tsuji, Hiroaki
, (2020/02/15)
The nickel-catalyzed hydroarylation of 1,3-dienes with arylboronic acids using a secondary homoallyl carbonate as a surrogate for the 1,3-diene and hydride source has been developed. The synthetic strategy allowed an efficient access to a wide array of hydroarylation products in high yields with high functional group compatibility without the use of an external hydride source. Mechanistic experiments indicated that the alkene-directed oxidative addition and subsequent β-hydride elimination would be a critical process in this transformation.
Dehydrative Coupling of Benzylic Alcohols Catalyzed by Br?nsted Acid/Lewis Base
B?ldl, Marlene,Fleischer, Ivana
supporting information, p. 5856 - 5861 (2019/08/07)
Traditional cross-coupling reactions show some disadvantages like the use of organohalides or the production of stoichiometric amounts of waste. The dehydrative homo- or heterocoupling of alcohols therefore arises as an interesting approach for a highly atom-economical formation of carbon–carbon bonds, since water is produced as the only by-product. We herein report a simple and direct, metal-free protocol for the synthesis of olefins by applying catalytic amounts of a sulfonic acid and triphenylphosphane under air. A variety of olefins could be synthesized from benzylic alcohols under relatively mild conditions. Additionally, dehydrative hydroarylation of benzylic alcohols with electron-rich arenes was possible by using only Br?nsted acid under otherwise same reaction conditions. We could show that phosphane additives are essential to overcome oligomerization as main side reaction by the occupancy of the reactive carbocation intermediate.
Silver triflate mediated dehydration of benzylic alcohols and vinyl hydrovinylation of styrene
Quillian, Brandon,Fields, Alexis E.,Chace, Desiree,Murrell Vickery, Amanda,Sharma, Mrinali,Zurwell, Dane,Bazemore, Joseph G.,Phan, Long,Thomas, Dorey,Padgett, Clifford W.
supporting information, p. 224 - 229 (2019/03/02)
The use of silver trifluoromethanesulfonate (silver triflate, AgOTf) as a halide abstraction reagent is pervasive in organometallic chemistry. However, recent reports suggest a “hidden” Br?nsted acid lurks within it that may catalyze purported metal-based catalysis. Presented herein are new reactions that are either catalyzed or promoted by the “hidden” acid, generated upon silver triflate degradation. 1-Phenylethanol dehydrates to styrene (1) upon reaction with AgOTf at 90 °C over 24 h, which slowly coverts to the vinyl hydrovinylation product (E)-1,3-diphenyl-1-butene, (2, 64%) over several days. While dehydration was observed with a number of benzylic alcohols to yield Zaitsev selective olefins, only 1-phenylethanol affords vinyl hydrovinylation products. Dehydration was not observed for primary and secondary alcohols, suggesting an acid catalyzed E1elimination reaction mechanism is at play. The degradation of silver triflate was found to be the source of the “hidden” Br?nsted acid, which demonstrated a dependence on the presence of light and oxygen. In the absence of light and oxygen, dehydration of 1-phenylethanol was severely stunted and 2 is not formed, but instead the ether product, oxy-bis(ethane-1,1-diyl)dibenzene (3), is afforded. The mesitylene internal standard also reacts with the in situ formed styrene to produce 2-(1-phenylethyl)mesitylene (4) through acid catalyzed electrophilic aromatic substitution. These reactions were monitored (products characterized) by GC-MS and/or 1H NMR spectroscopic methods. We present herein the details of these reactions and our characterization methods.
Nickel-Catalyzed Direct Coupling of Allylic Alcohols with Organoboron Reagents
Wang, Gaonan,Gan, Yi,Liu, Yuanhong
supporting information, p. 916 - 920 (2018/09/22)
The direct coupling of allylic alcohols with arylboronic acids or their derivatives catalyzed by Ni(cod)2 in the presence of a catalytic amount of base has been developed. A wide variety of allylic substrates or arylboronic acids turned out to be applicable to this catalytic system. The present method does not require the use of ligands for stabilizing the nickel catalyst in most cases or additional activators for activation of allylic alcohols.
Asymmetric synthesis via stereospecific C-N and C-O bond activation of alkyl amine and alcohol derivatives
Pound, Sarah M.,Watson, Mary P.
, p. 12286 - 12301 (2018/11/20)
This perspective showcases our development of benzylic and allylic amine and alcohol derivatives as electrophiles for stereospecific, nickel-catalyzed cross-coupling reactions, as well as the prior art that inspired our efforts. The success of our effort
[Pd(acac)(L)2][BF4] (L?=?morpholine, diethylamine, dibutylamine, dioctylamine): Synthesis, structure and their catalytic activity
Suslov,Bykov,Ratovskii,Abramov,Pahomova,Ushakov,Voronov,Tkach
, p. 411 - 421 (2016/12/26)
Cationic acetylacetonate bis(secondary amine) palladium (II) complexes were synthesized by nitrile substitution of [Pd(acac)(MeCN)2][BF4] with L (L?=?morpholine, diethylamine, dibutylamine, dioctylamine) which yielded [Pd(acac)(L)2][BF4] as a mononuclear species with chelating acac ligand. An X-ray diffraction, NMR, IR and DFT study of [Pd(acac){morpholine}2][BF4] establishes the presence of hydrogen bonding between the morpholine ligand and [BF4]? anion. Crystallographic defects in the crystal and presence of pseudocrystalline structure in solution of [Pd(acac){morpholine}2][BF4] were assumed to explain IR spectra features. Preliminary investigations into the polymerization of norbornene, dimerization of styrene, and telomerization of 1,3-butadiene with diethylamine were performed.
