32464-98-5Relevant articles and documents
Stable hydrazone-linked chiral covalent organic frameworks: Synthesis, modi?cation, and chiral signal inversion from monomers
Yan, Yilun,Li, Xinle,Chen, Gui,Zhang, Kai,Tang, Xihao,Zhang, Shuyuan,Zheng, Shengrun,Fan, Jun,Zhang, Weiguang,Cai, Songliang
supporting information, p. 107 - 112 (2020/12/21)
The designed synthesis of chiral covalent organic frameworks (COFs) featuring intriguing properties is fairly scant and remains a daunting synthetic challenge. Here we develop a de novo synthesis of an enantiomeric pair of 2D hydroxyl-functionalized hydra
TRICYCLIC PYRIDONES AND PYRIMIDONES
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Paragraph 1101-1103, (2021/06/26)
A compound of Formula (I) is provided: (I) where the variables are defined herein.
Benzoxaborole Catalyst for Site-Selective Modification of Polyols
Kusano, Shuhei,Miyamoto, Shoto,Matsuoka, Aki,Yamada, Yuji,Ishikawa, Ryuta,Hayashida, Osamu
supporting information, p. 1598 - 1602 (2020/02/11)
The site-selective modification of polyols bearing several hydroxyl groups without the use of protecting groups remains a significant challenge in synthetic chemistry. To address this problem, novel benzoxaborole derivatives were designed as efficient catalysts for the highly site-selective and protecting-group-free modification of polyols. To identify the effective substituent groups enhancing the catalytic activity and selectivity, a series of benzoxaborole catalysts 1a–k were synthesized. In-depth analysis for the substituent effect revealed that 1i–k, bearing multiple electron-withdrawing fluoro- and trifluoromethyl groups, exhibited the greatest catalytic activity and selectivity. Moreover, 1i-catalyzed benzoylation, tosylation, benzylation, and glycosylation of various cis-1,2-diol derivatives proceeded with good yield and site-selective manner.
Regioselective Sulfonylation/Acylation of Carbohydrates Catalyzed by FeCl3 Combined with Benzoyltrifluoroacetone and Its Mechanism Study
Dong, Hai,Liu, Yu,Lv, Jian,Zhu, Jia-Jia
, p. 3307 - 3319 (2020/03/25)
A catalytic amount of FeCl3 combined with benzoyl trifluoroacetone (Hbtfa) (FeCl3/Hbtfa = 1/2) was used to catalyze sulfonylation/acylation of diols and polyols using diisopropylethylamine (DIPEA) or potassium carbonate (K2CO3) as a base. The catalytic system exhibited high catalytic activity, leading to excellent isolated yields of sulfonylation/acylation products with high regioselectivities. Mechanism studies indicated that FeCl3 initially formed [Fe(btfa)3] (btfa = benzoyl trifluoroacetonate) with twice the amount of Hbtfa under basic conditions in the solvent acetonitrile at room temperature. Then, Fe(btfa)3 and two hydroxyl groups of the substrates formed a five- or six-membered ring intermediate in the presence of the base. The subsequent reaction between the cyclic intermediate and a sulfonylation reagent led to the selective sulfonylation of the substrate. All key intermediates were captured in the high-resolution mass spectrometry assay, therefore demonstrating this mechanism for the first time.
Enantiodivergent syntheses of (+)- and (?)-1-(2,6-dimethylphenoxy)propan-2-ol: A way to access (+)- and (?)-mexiletine from D-(+)-mannitol
Manna, Avrajit,Chatterjee, Sandip,Chakraborty, Ipsita,Bhaumik, Tanurima
, (2020/01/08)
Chiron approach was used to acquire optically pure (R)- and (S)-1-(2,6-dimethylphenoxy)propan-2-ol, immediate precursors of (S)- and (R)-mexiletines, respectively. Two different routes were followed from a D-mannitol-derived optically pure common precursor to get the enantiomeric alcohols separately. Comparison of their specific rotation values with the corresponding literature values as well as exact mirror-image relationship between their CD curves proved their high enantiopurity. These alcohols were then transformed to the corresponding amine-drugs in an efficient one-step process instead of two steps described in the literature.
2 Tyrosine kinase mediated signal transduction inhibitors
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Paragraph 0556; 0557; 0558, (2019/09/17)
Disclosed herein are compounds of Formula (), and pharmaceutically acceptable salts thereof, wherein R, R, R, R, R, X, X, X, X, X, and n are as defined herein, pharmaceutical compositions comprising same, and methods of preparation and use.
New functional chiral P-based ligands and application in ruthenium-catalyzed enantioselective transfer hydrogenation of ketones
Meri?, Nermin,Kayan, Cezmi,Gürbüz, Nevin,Karakaplan, Mehmet,Binbay, Nil Ertekin,Aydemir, Murat
, p. 1739 - 1749 (2017/10/26)
Metal-catalyzed asymmetric transfer hydrogenation is a powerful and practical method for the reduction of ketones to produce the corresponding secondary alcohols, which are valuable building blocks in the pharmaceutical, perfume, and agrochemical industries. Hence, a series of novel chiral β-amino alcohols were synthesized by chiral amines with regioselective ring opening of (S)-propylene oxide or reaction with (S)-(+)-2-hydroxypropyl p-toluenesulfonate by a straightforward method. The chiral ruthenium catalytic systems generated from [Ru(arene)(μ-Cl)Cl]2 complexes and chiral phosphinite ligands based on amino alcohol derivatives were employed in asymmetric transfer hydrogenation of ketones to give the corresponding optically active alcohols; (2S)-1-{[(2S)-2-[(diphenylphosphanyl)oxy]propyl][(1R)-1-phenylethyl]amino}propan-2-yldiphenylphosphinitobis[dichol-oro(η6-benzene)ruthenium(II)] acts an excellent catalyst in the reduction of α-naphthyl methyl ketone, giving the corresponding alcohol with up to 99% ee. The substituents on the backbone of the ligands were found to have a remarkable effect on both the conversion and enantioselectivity of the catalysts. Furthermore, this transfer hydrogenation is characterized by low reversibility under these conditions.
9-Hetero-10-boraanthracene-derived borinic acid catalysts for regioselective activation of polyols
Dimitrijevic, Elena,Taylor, Mark S.
, p. 3298 - 3303 (2013/07/26)
Heteraborinine-derived borinic acids serve as efficient catalysts for regioselective monofunctionalization of di- and polyols. Arylborinic acids of this type, wherein the B-OH group is incorporated into a 6π electron system, display both improved catalytic activity for functionalization of diols and enhanced stability towards air oxidation relative to the 'parent' diphenylborinic acid (Ph2BOH). These properties enable their applications at loadings as low as 0.1 mol% and without the need for a stabilizing precatalyst ligand (e.g., ethanolamine). Complexation studies, computation and kinetic data suggest that while the heteraborinine-derived borinic acids show significantly lower association constants with substrates than Ph2BOH, this effect is more than compensated for by the increased nucleophilicity of their tetracoordinate diol adducts.
Regioselective, borinic acid-catalyzed monoacylation, sulfonylation and alkylation of diols and carbohydrates: Expansion of substrate scope and mechanistic studies
Lee, Doris,Williamson, Caitlin L.,Chan, Lina,Taylor, Mark S.
supporting information; experimental part, p. 8260 - 8267 (2012/07/14)
Synthetic and mechanistic aspects of the diarylborinic acid-catalyzed regioselective monofunctionalization of 1,2- and 1,3-diols are presented. Diarylborinic acid catalysis is shown to be an efficient and general method for monotosylation of pyranoside derivatives bearing three secondary hydroxyl groups (7 examples, 88% average yield). In addition, the scope of the selective acylation, sulfonylation, and alkylation is extended to 1,2- and 1,3-diols not derived from carbohydrates (28 examples); the efficiency, generality, and operational simplicity of this method are competitive with those of state-of-the-art protocols including the broadly applied organotin-catalyzed or -mediated reactions. Mechanistic details of the organoboron-catalyzed processes are explored using competition experiments, kinetics, and catalyst structure-activity relationships. These experiments are consistent with a mechanism in which a tetracoordinate borinate complex reacts with the electrophilic species in the turnover-limiting step of the catalytic cycle.
Synthesis of C2-symmetric chiral amino alcohols: Their usage as organocatalysts for enantioselective opening of epoxide ring
Turgut, Yilmaz,Aral, Tarik,Karakaplan, Mehmet,Deniz, Pinar,Hosgoren, Halil
experimental part, p. 3365 - 3377 (2011/01/04)
A series of -amino alcohols derivatives were synthesized from (R)-2-amino-1-butanol and (S)-1,2-propanediol, and they have been used as organocatalaysts in the racemic ring opening of epoxide in good yields with high enantiomeric excess (up to 97%). Copyright
