5720-06-9Relevant articles and documents
Asymmetric 1,4-Addition of Arylboronic Acids to β,γ-Unsaturated α-Ketoesters using Heterogeneous Chiral Metal Nanoparticle Systems
Miyamura, Hiroyuki,Yasukawa, Tomohiro,Zhu, Zhiyuan,Kobayashi, Shū
supporting information, p. 353 - 359 (2019/12/15)
Asymmetric 1,4-addition reactions with β,γ-unsaturated α-ketoesters are valuable because the resulting chiral ketoester compounds can be converted into various useful species that are often used as chiral building blocks in drug and natural product synthesis. However, β,γ-unsaturated α-ketoesters have two reactive points in terms of nucleophilic additions, which will lead to the 1,4-adduct, the 1,2-adduct and to the combined 1,4- and 1,2-adduct. Therefore, controlling this chemoselectivity is an important factor for the development of these transformations. Here, we developed an asymmetric 1,4-addition of aryl boronic acids to β,γ-unsaturated α-ketoesters by using heterogeneous chiral rhodium nanoparticle systems with a chiral diene ligand bearing a secondary amide moiety. The newly developed polydimethylsilane-immobilized rhodium nanoparticle catalysts showed high activity, high chemoselectivity, and excellent enantioselectivity, and this is the first heterogeneous catalytic system for this asymmetric reaction. Metal nanoparticle catalysts were recovered and reused without loss of activity or leaching of metal. (Figure presented.).
Aryl boronic acid preparation method
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Paragraph 0033-0040, (2020/01/25)
The invention belongs to the technical field of fine chemical engineering, and relates to an aryl boronic acid preparation method. In the prior art, aryl boronic acid as a novel safe and environmentally-friendly arylation reagent is widely used in scientific research and production of various fine chemicals containing aryl structures in the fields of medicines, pesticides, advanced materials and the like; and the aryl boronic acid compound preparation method reported in the disclosed literature has problems of harsh reaction conditions and high cost. A purpose of the invention is to provide amethod, wherein an aryl boron compound is formed by carrying out a reaction on a Grignard reagent and trialkyl borate under mild conditions, the composition of the aryl boron compound is converted from the main component diaryl borate into the main component aryl borate, and the aryl borate is hydrolyzed to obtain aryl boric acid, so that the preparation cost of the acyl aryl boric acid compound can be remarkably reduced, and the method has good practical application prospect.
Chemoselective Rhodium-Catalyzed Borylation of Bromoiodoarenes under Mild Conditions
Varni, Anthony J.,Bautista, Michael V.,Noonan, Kevin J.T.
, p. 6770 - 6777 (2020/07/21)
A chemoselective rhodium-catalyzed borylation has been developed for the preparation of aryl boronate esters. The reaction proceeds under mild conditions with excellent selectivity for C-I bonds in bromoiodoarenes and exhibits broad functional group tolerance. This procedure can act as a complementary approach toward bifunctional arenes along with other metal-catalyzed borylations. Additionally, the reaction's utility in the preparation of monomers for metal-catalyzed cross-coupling polymerization is demonstrated.
Copper-Catalyzed Monoorganylation of Trialkyl Borates with Functionalized Organozinc Pivalates
Fu, Ying,Gou, Bei-Lei,Shi, Chun-Zhao,Du, Zhengyin,Shen, Tong
, p. 4253 - 4257 (2018/09/18)
Organozinc pivalates, a recently developed air- and moisture-stable organozinc species, were found for the first time as excellent organometallic species in the monoorganylation of trialkyl borates whereby boronic acids were prepared in high yields. The significant advantage of organozinc pivalates over another previously employed organometallic reagents, e. g., organolithium reagents, Grignard reagents and organozinc halides, is that the generation of multiorganylation byproducts such as borinic acids and trialkylboranes were completely suppressed. Additionally, the in situ generated boronates could be directly arranged into Suzuki-Miyaura type cross-coupling reactions to produce biaryls in high yields.
Bedford-type palladacycle-catalyzed miyaura borylation of aryl halides with tetrahydroxydiboron in water
Zernickel, Anna,Du, Weiyuan,Ghorpade, Seema A.,Sawant, Dinesh N.,Makki, Arwa A.,Sekar, Nagaiyan,Eppinger, J?rg
, p. 1842 - 1851 (2018/02/23)
A mild aqueous protocol for palladium catalyzed Miyaura borylation of aryl iodides, aryl bromides and aryl chlorides with tetrahydroxydiboron (BBA) as a borylating agent is developed. The developed methodology requires low catalyst loading of Bedford-type palladacycle catalyst (0.05 mol %) and works best under mild reaction conditions at 40 °C in short time of 6 h in water. In addition, our studies show that for Miyaura borylation using BBA in aqueous condition, maintaining a neutral reaction pH is very important for reproducibility and higher yields of corresponding borylated products. Moreover, our protocol is applicable for a broad range of aryl halides, corresponding borylated products are obtained in excellent yields up to 93% with 29 examples demonstrating its broad utility and functional group tolerance.
Axially chiral tridentate isoquinoline derived ligands for diethylzinc addition to aldehydes
Sweetman, Brian A.,Guiry, Patrick J.
, p. 5567 - 5581 (2018/08/09)
The synthesis and resolution of new tridentate isoquinoline-derived ligands has been developed. The key steps in the synthetic sequence include successive, chemo-selective Suzuki-Miyaura cross-couplings of 1,3-dichloroisoquinoline with suitable arylboronic acids. The new ligands prepared in this manner were resolved either via molecular complexation with N-benzylcinchonidinium chloride as with 1-[3-(2-hydroxyphenyl)isoquinolin-1-yl]naphthalen-2-ol or via chromatographic separation of its epimeric camphorsulfonates as for 1,3-bis-(2-hydroxynaphthalen-1-yl)isoquinoline. 4-tert-Butyl-2-chloro-6-[1-(2-hydroxymethylnaphthalen-1-yl)isoquinolin-3-yl]phenol was resolved by chiral semi-preparative HPLC. The application of these ligands in the diethylzinc addition to aldehydes was investigated. In certain cases, the desired secondary alcohols were obtained in high yield with excellent enantiomeric excess (ee > 99%) at low catalyst loading (1 mol%).
An efficient method for the hydrolysis of potassium organotrifluoroborates promoted by montmorillonite K10
Silva, Renato L.,Santos, Cosme S.,Santos, Jonh A. M.,Oliveira, Roberta A.,Menezes, Paulo H.,Freitas, Juliano C. R.
, p. 1777 - 1785 (2018/09/04)
An efficient and non-expensive method for conversion of diverse potassium organotrifluoroborates to their corresponding boronic acids promoted by montmorillonite K10 using water as the reaction solvent is described. Further interconversion of potassium organotrifluoroborates to their corresponding boronic esters, via boronic acid intermediates was also successfully accomplished. The products were obtained in good yields, being the rate of hydrolysis influenced by the type of substituent present in the boronic acid.
Borinic Acids via Direct Arylation of Amine-Borane Complexes: An Air- and Water-Stable Boron Source
Richard, Jimmy,Birepinte, Mélodie,Charbonnier, Jean Baptiste,Liautard, Virginie,Pinet, Sandra,Pucheault, Mathieu
, p. 736 - 744 (2017/02/15)
A synthesis of borinic acids and borinates was optimized using amine-borane complexes as a water and air insensitive borylating agent. The reaction operates under convenient conditions using a non-cryogenic temperature and with no flash chromatography, and it gives no boron impurities. The reaction proceeds through a tandem dehydrogenation-double addition mechanism.
Synthesis and evaluation of sulfonamide derivatives as potent Human Uric Acid Transporter 1 (hURAT1) inhibitors
Yang, Xintuo,Pang, Xuehai,Fan, Lei,Li, Xinghai,Chen, Yuanwei
supporting information, p. 1919 - 1922 (2017/04/10)
This letter presents synthesis and structure-activity relationship study of sulfonamide derivatives as inhibitors of Human Uric Acid Transporter 1 (hURAT1). Among all tested sulfonamide derivatives, compounds 9b, 16i and 19b exhibited excellent inhibition activity with IC50 value of 10, 2, and 83?nM, respectively. In addition, compounds 9b and 19b demonstrated moderate PK profile in rats.
Evidence for Oxidative Decay of a Ru-Bound Ligand during Catalyzed Water Oxidation
Kagalwala, Husain N.,Tong, Lianpeng,Zong, Ruifa,Kohler, Lars,Ahlquist, M?rten S. G.,Fan, Ting,Gagnon, Kevin J.,Thummel, Randolph P.
, p. 2607 - 2615 (2017/06/01)
In the evaluation of systems designed for catalytic water oxidation, ceric ammonium nitrate (CAN) is often used as a sacrificial electron acceptor. One of the sources of failure for such systems is oxidative decay of the catalyst in the presence of the st
