Xn:Harmful;
83-33-0Relevant academic research and scientific papers
Photoinduced Double Addition of Acetylene to 3-Oxocyclopent-1-ene-1-carbonitrile or 3-Oxocyclopent-1-enyl Acetate Leading to 2,3-Dihydro-1H-inden-1-one and Other Rearranged Products
Cavazza, Marino,Guella, Graziano,Pietra, Francesco
, p. 1608 - 1615 (1988)
UV Irradiation of 3-oxocyclopent-1-enyl acetate (17) and acetylene in MeCN at 0 deg C gives, besides the product of normal enone-alkyne cycloaddition (cis-4-oxobicyclohept-6-en-1-yl acetate, 18) and its product of oxa-di-?-methane rearrangement (5-oxotricyclo2,7>hept-2-yl acetate, 19), unexpected products of further addition of a molar equivalent of acetylene.These are indanone (= 2,3-dihydro-1H-inden-1-one, 16), in 21percent yield, cis-1-cisoid-1,2-cis-2- (20) and cis-1-transoid-1,2-cis-2,7-oxotricyclo2,5>non-3-en-1-yl acetate (21), 4-oxo-7-'exo'-vinyltricyclo2,6>hept-2-yl acetate (22), cis-4-oxo-6 -'endo'- (23) and cis-4-oxo-6-'exo'-vinylbicyclohept-1-yl acetate (24), and cis-4-oxo-7-'exo'-vinylbicyclohept-1-yl acetate (25).At least in part, indanone must be formed via intermediates 20 and 21.In fact, on heating a 9:1 mixture 20/21, indanone is obtained quantitatively.With 3-oxocyclopent-1-ene-1-carbonitrile (15) in place of 17, indanone is formed in lower (8percent) yield besides much tars.
Solid state asymmetric synthesis of chiral crystals of 5- and 7-membered ring ketones
Xu, Xianzhu,Wang, Peng,Xia, Wujiong,Yang, Chao
, p. 150 - 151 (2008)
The results of absolute asymmetric photochemical studies on 5- and 7-membered spiroketones in the solid state are described. Photolysis of 7-membered spiroketone undergoing a Norrish type II cyclisation reaction gives enantioselectivity excesses up to 93%. Irradiation of 5-membered spiroketone afforded a racemic product. The results are rationalised by the X-ray crystallographic method.
Covalent Linkage of an R-ω-Transaminase to a d-Amino Acid Oxidase through Protein Splicing to Enhance Enzymatic Catalysis of Transamination
Du, Kun,Li, Rong,Zhang, Dongrui,Feng, Wei
, p. 701 - 709 (2019)
R-ω-Transaminases (RTAs) catalyse the conversion of R-configured amines [e.g., (R)-1-phenylethylamine] into the corresponding ketones (e.g., acetophenone), by transferring an amino group from an amino donor [e.g., (R)-1-phenylethylamine] onto an amino acceptor (e.g., pyruvate), resulting in a co-product (e.g., d-alanine). d-Alanine can be deaminated back to pyruvate by d-amino acid oxidase (DAAOs). Here, through in vivo subunit splicing, the N terminus of an RTA subunit (RTAS) was specifically ligated to the C terminus of a DAAO subunit (DAAOS) through native peptide bonds (RTA&DAAO). RTAS is in close proximity to DAAOS, at a molecular-scale distance. Thus the transfer of pyruvate and d-alanine between RTA and DAAO can be directional and efficient. Pyruvate→d-alanine→pyruvate cycles are efficiently formed, thus promoting the forward transamination reaction. In a different, in vitro noncovalent approach, based on coiled-coil association, the RTAS N terminus was specifically associated with the DAAOS C terminus (RTA#DAAO). In addition, the two mixed individual enzymes (RTA+DAAO) were also studied. RTA&DAAO has a shorter distance between the paired subunits (RTAS–DAAOS) than RTA#DAAO, and the number of the paired subunits is higher than in the case of RTA#DAAO, whereas RTA+DAAO cannot form the paired subunits. RTA&DAAO exhibited a transamination catalysis efficiency higher than that of RTA#DAAO and much higher than that of RTA+DAAO.
Improved synthetic route to methyl 1-fluoroindan-1-carboxylate (FICA Me ester) and 4-methyl derivatives
Koyanagi, Jyunichi,Kamei, Tomoyo,Ishizaki, Miyuki,Nakamura, Hiroshi,Takahashi, Tamiko
, p. 816 - 819 (2014)
An improved synthetic route has been developed for the preparation of methyl 1-fluoroindan-1-carboxylate (FICA Me ester) from 1-indanone. Methyl 4-methyl-1-fluoroindan-1-carboxylate (4-Me-FICA Me ester) was also prepared following the same procedure.
4CzIPN catalyzed photochemical oxidation of benzylic alcohols
Zhang, Heng,Guo, Tianyun,Wu, Mingzhong,Huo, Xing,Tang, Shouchu,Wang, Xiaolei,Liu, Jian
supporting information, (2021/02/20)
A green photoredox oxidation of benzylic primary and secondary alcohols to aldehydes and ketones with air as an oxidant was reported. The oxidation shows broad substrate scope and excellent selectivity over benzylic alcohols to the aliphatic alcohols. Further mechanistic studies revealed a quinuclidine mediated HAT process, and blue LEDs promoted 4CzlPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene) photoredox cycle were involved in our oxidation.
Engineering the large pocket of an (S)-selective transaminase for asymmetric synthesis of (S)-1-amino-1-phenylpropane
Liu, He,Wang, Hualei,Wei, Dongzhi,Xie, Youyu,Xu, Feng,Xu, Xiangyang,Yang, Lin
, p. 2461 - 2470 (2021/04/22)
Amine transaminases offer an environmentally benign chiral amine asymmetric synthesis route. However, their catalytic efficiency towards bulky chiral amine asymmetric synthesis is limited by the natural geometric structure of the small pocket, representing a great challenge for industrial applications. Here, we rationally engineered the large binding pocket of an (S)-selective ?-transaminase BPTA fromParaburkholderia phymatumto relieve the inherent restriction caused by the small pocket and efficiently transform the prochiral aryl alkyl ketone 1-propiophenone with a small substituent larger than the methyl group. Based on combined molecular docking and dynamic simulation analyses, we identified a non-classical substrate conformation, located in the active site with steric hindrance and undesired interactions, to be responsible for the low catalytic efficiency. By relieving the steric barrier with W82A, we improved the specific activity by 14-times compared to WT. A p-p stacking interaction was then introduced by M78F and I284F to strengthen the binding affinity with a large binding pocket to balance the undesired interactions generated by F44. T440Q further enhanced the substrate affinity by providing a more hydrophobic and flexible environment close to the active site entry. Finally, we constructed a quadruple variant M78F/W82A/I284F/T440Q to generate the most productive substrate conformation. The 1-propiophenone catalytic efficiency of the mutant was enhanced by more than 470-times in terms ofkcat/KM, and the conversion increased from 1.3 to 94.4% compared with that of WT, without any stereoselectivity loss (ee > 99.9%). Meanwhile, the obtained mutant also showed significant activity improvements towards various aryl alkyl ketones with a small substituent larger than the methyl group ranging between 104- and 230-fold, demonstrating great potential for the efficient synthesis of enantiopure aryl alkyl amines with steric hindrance in the small binding pocket.
Enantioselective oxidation of secondary alcohols by the flavoprotein alcohol oxidase from Phanerochaete chrysosporium
Tjallinks, Gwen,Martin, Caterina,Fraaije, Marco W.
, (2021/05/03)
The enantioselective oxidation of secondary alcohols represents a valuable approach for the synthesis of optically pure compounds. Flavoprotein oxidases can catalyse such selective transformations by merely using oxygen as electron acceptor. While many flavoprotein oxidases preferably act on primary alcohols, the FAD-containing alcohol oxidase from Phanerochaete chrysosporium was found to be able to perform kinetic resolutions of several secondary alcohols. By selective oxidation of the (S)-alcohols, the (R)-alcohols were obtained in high enantiopurity. In silico docking studies were carried out in order to substantiate the observed (S)-selectivity. Several hydrophobic and aromatic residues in the substrate binding site create a cavity in which the substrates can comfortably undergo van der Waals and pi-stacking interactions. Consequently, oxidation of the secondary alcohols is restricted to one of the two enantiomers. This study has uncovered the ability of an FAD-containing alcohol oxidase, that is known for oxidizing small primary alcohols, to perform enantioselective oxidations of various secondary alcohols.
Chiral Yolk-Shell MOF as an Efficient Nanoreactor for Asymmetric Catalysis in Organic-Aqueous Two-Phase System
Shi, Shunli,Zhong, Yicheng,Hu, Zhuo,Wang, Lei,Yuan, Mingwei,Ding, Shunmin,Wang, Shuhua,Chen, Chao
supporting information, p. 12714 - 12718 (2021/09/11)
It remains a great challenge to introduce large and efficient homogeneous asymmetric catalysts into MOFs and other microporous materials as well as retain their degrees of freedom. Herein, a new heterogeneous strategy of homogeneous chiral catalysts is proposed, that is, to construct a yolk-shell MOFs-confined, large-size, and highly efficient homogeneous chiral catalyst, which can be used as a nanoreactor for asymmetric catalytic reactions.
Organotellurium-catalyzed oxidative deoximation reactions using visible-light as the precise driving energy
Deng, Xin,Qian, Rongrong,Zhou, Hongwei,Yu, Lei
supporting information, p. 1029 - 1032 (2020/10/23)
Irradiated by visible light, the recyclable (PhTe)2-catalyzed oxidative deoximation reaction could occur under mild conditions. In comparison with the thermo reaction, the method employed reduced catalyst loading (1 mol% vs. 2.5 mol%), but afforded elevated product yields with expanded substrate scope. This work demonstrated that for the organotellurium-catalyzed reactions, visible light might be an even more precise driving energy than heating because it could break the Te–Te bond accurately to generate the active free radical catalytic intermediates without damaging the fragile substituents (e.g., heterocycles) of substrates. The use of O2 instead of explosive H2O2 as oxidant affords safer reaction conditions from the large-scale application viewpoint.
A metal-free method for the facile synthesis of indanonesviathe intramolecular hydroacylation of 2-vinylbenzaldehyde
He, Guoxue,Ma, Jinyu,Zhou, Jianhui,Li, Chunpu,Liu, Hong,Zhou, Yu
supporting information, p. 1036 - 1040 (2021/02/09)
A facile method for the synthesis of indanones was developed under metal- and additive-free conditions, whereinl-proline served as an efficient and environmentally benign catalyst. Compared with previously synthesized indanones, synthesis by the transition-metal-catalyzed intramolecular hydroacylation of 2-vinylbenzaldehyde provided a more green synthetic pathway to indanone scaffolds with good to excellent yields. More importantly, it could be used to synthsize the anti-AD drug donepezil.
