3772-43-8Relevant academic research and scientific papers
Scalable and Phosphine-Free Conversion of Alcohols to Carbon-Heteroatom Bonds through the Blue Light-Promoted Iodination Reaction
Liu, Bin,Elder, W. Zachary,Miyake, Garret M.
, p. 3717 - 3727 (2020/03/04)
One of the fundamental and highly valuable transformations in organic chemistry is the nucleophilic substitution of alcohols. Traditionally, these reactions require strategies that employ stoichiometric hazardous reagents and are associated with difficulty in purification of the by-products. To overcome these challenges, here, we report a simple route toward the diverse conversion of alcohols via an SN2 pathway, in which blue light-promoted iodination is used to form alkyl iodide intermediates from simple unreactive alcohols. The scope of the process tolerates a range of nucleophiles to construct C-N, C-O, C-S, and C-C bonds. Furthermore, we also demonstrate that this method can be used for the preparation and late-stage functionalization of pharmaceuticals, as highlighted by the syntheses of thiocarlide, butoxycaine, and pramoxine.
Metal-Free Etherification of Aryl Methyl Ether Derivatives by C-OMe Bond Cleavage
Wang, Xueqiang,Li, Chenchen,Wang, Xia,Wang, Qingli,Dong, Xiu-Qin,Duan, Abing,Zhao, Wanxiang
supporting information, p. 4267 - 4272 (2018/07/29)
A general and efficient protocol was developed for the synthesis of aryl alkyl ethers through metal-free C-OMe bond cleavage under mild reaction conditions. This process displays a wide scope of methoxyarenes and alcohols, including primary, secondary, and tertiary alcohols, as well as natural products, pharmaceuticals, and biologically active alcohols. DFT calculations and experimental results simultaneously confirm that a potassium ion plays a critical role in the activation of methoxy group via binding with the nitrile and provide support for an SNAr mechanism.
Benzene C-H Etherification via Photocatalytic Hydrogen-Evolution Cross-Coupling Reaction
Zheng, Yi-Wen,Ye, Pan,Chen, Bin,Meng, Qing-Yuan,Feng, Ke,Wang, Wenguang,Wu, Li-Zhu,Tung, Chen-Ho
, p. 2206 - 2209 (2017/05/12)
Aryl ethers can be constructed from the direct coupling between the benzene C-H bond and the alcohol O-H bond with the evolution of hydrogen via the synergistic merger of photocatalysis and cobalt catalysis. Utilizing the dual catalyst system consisting of 3-cyano-1-methylquinolinum photocatalyst and cobaloxime, intermolecular etherification of arenes with various alcohols and intramolecular alkoxylation of 3-phenylpropanols with formation of chromanes are accomplished. These reactions proceed at remarkably mild conditions, and the sole byproduct is equivalent hydrogen gas.
Efficient fluoride-catalyzed conversion of CO2 to CO at room temperature
Lescot, Camille,Nielsen, Dennis U.,Makarov, Ilya S.,Lindhardt, Anders T.,Daasbjerg, Kim,Skrydstrup, Troels
supporting information, p. 6142 - 6147 (2014/05/20)
A protocol for the efficient and selective reduction of carbon dioxide to carbon monoxide has been developed. Remarkably, this oxygen abstraction step can be performed with only the presence of catalytic cesium fluoride and a stoichiometric amount of a disilane in DMSO at room temperature. Rapid reduction of CO2 to CO could be achieved in only 2 h, which was observed by pressure measurements. To quantify the amount of CO produced, the reduction was coupled to an aminocarbonylation reaction using the two-chamber system, COware. The reduction was not limited to a specific disilane, since (Ph 2MeSi)2 as well as (PhMe2Si)2 and (Me3Si)3SiH exhibited similar reactivity. Moreover, at a slightly elevated temperature, other fluoride salts were able to efficiently catalyze the CO2 to CO reduction. Employing a nonhygroscopic fluoride source, KHF2, omitted the need for an inert atmosphere. Substituting the disilane with silylborane, (pinacolato)BSiMe2Ph, maintained the high activity of the system, whereas the structurally related bis(pinacolato)diboron could not be activated with this fluoride methodology. Furthermore, this chemistry could be adapted to 13C-isotope labeling of six pharmaceutically relevant compounds starting from Ba13CO 3 in a newly developed three-chamber system.
SYSTEM PROVIDING CONTROLLED DELIVERY OF GASEOUS CO FOR CARBONYLATION REACTIONS
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Page/Page column 100; 101, (2012/06/30)
A carbonylation system comprising at least one carbon monoxide producing chamber and at least one carbon monoxide consuming chamber forming an interconnected multi-chamber system, said interconnection allowing carbon monoxide to pass from the at least one carbon monoxide producing chamber to the at least one carbon monoxide consuming chamber, said at least one carbon monoxide producing chamber containing a reaction mixture comprising a carbon monoxide precursor and a catalyst, said at least one carbon monoxide consuming chamber being suitable for carbonylation reactions, said interconnected multi- chamber system being sealable from the surrounding atmosphere during carbonylation.
Ex situ generation of stoichiometric and substoichiometric 12CO and 13CO and its efficient incorporation in palladium catalyzed aminocarbonylations
Hermange, Philippe,Lindhardt, Anders T.,Taaning, Rolf H.,Bjerglund, Klaus,Lupp, Daniel,Skrydstrup, Troels
supporting information; experimental part, p. 6061 - 6071 (2011/06/19)
A new technique for the ex situ generation of carbon monoxide (CO) and its efficient incorporation in palladium catalyzed carbonylation reactions was achieved using a simple sealed two-chamber system. The ex situ generation of CO was derived by a palladium catalyzed decarbonylation of tertiary acid chlorides using a catalyst originating from Pd(dba)2 and P(tBu)3. Preliminary studies using pivaloyl chloride as the CO-precursor provided an alternative approach for the aminocarbonylation of 2-pyridyl tosylate derivatives using only 1.5 equiv of CO. Further design of the acid chloride CO-precursor led to the development of a new solid, stable, and easy to handle source of CO for chemical transformations. The synthesis of this CO-precursor also provided an entry point for the late installment of an isotopically carbon-labeled acid chloride for the subsequent release of gaseous [ 13C]CO. In combination with studies aimed toward application of CO as the limiting reagent, this method provided highly efficient palladium catalyzed aminocarbonylations with CO-incorporations up to 96%. The ex situ generated CO and the two-chamber system were tested in the synthesis of several compounds of pharmaceutical interest and all of them were labeled as their [ 13C]carbonyl counterparts in good to excellent yields based on limiting CO. Finally, palladium catalyzed decarbonylation at room temperature also allowed for a successful double carbonylation. This new protocol provides a facile and clean source of gaseous CO, which is safely handled and stored. Furthermore, since the CO is generated ex situ, excellent functional group tolerance is secured in the carbonylation chamber. Finally, CO is only generated and released in minute amounts, hence, eliminating the need for specialized equipment such as CO-detectors and equipment for running high pressure reactions.
A general and efficient catalyst for palladium-catalyzed C-O coupling reactions of aryl halides with primary alcohols
Gowrisankar, Saravanan,Sergeev, Alexey G.,Anbarasan, Pazhamalai,Spannenberg, Anke,Neumann, Helfried,Beller, Matthias
supporting information; experimental part, p. 11592 - 11598 (2010/10/02)
An efficient procedure for palladium-catalyzed coupling reactions of (hetero)aryl bromides and chlorides with primary aliphatic alcohols has been developed. Key to the success is the synthesis and exploitation of the novel bulky di-1-adamantyl-substituted bipyrazolylphosphine ligand L6. Reaction of aryl halides including activated, nonactivated, and (hetero)aryl bromides as well as aryl chlorides with primary alcohols gave the corresponding alkyl aryl ethers in high yield. Noteworthy, functionalizations of primary alcohols in the presence of secondary and tertiary alcohols proceed with excellent regioselectivity.
