455-67-4Relevant academic research and scientific papers
Iridium Complexes as Efficient Catalysts for Construction of α-Substituted Ketones via Hydrogen Borrowing of Alcohols in Water
Luo, Nianhua,Zhong, Yuhong,Wen, Huiling,Shui, Hongling,Luo, Renshi
, p. 1355 - 1364 (2021/03/03)
Ketones are of great importance in synthesis, biology, and pharmaceuticals. This paper reports an iridium complexes-catalyzed cross-coupling of alcohols via hydrogen borrowing, affording a series of α-alkylated ketones in high yield (86 %–95 %) and chemoselectivities (>99 : 1). This methodology has the advantages of low catalyst loading (0.1 mol%) and environmentally benign water as the solvent. Studies have shown the amount of base has a great impact on chemoselectivities. Meanwhile, deuteration experiments show water plays an important role in accelerating the reduction of the unsaturated ketones intermediates. Remarkably, a gram-scale experiment demonstrates this methodology of iridium-catalyzed cross-coupling of alcohols has potential application in the practical synthesis of α-alkylated ketones.
Manganese complex-catalyzed oxidation and oxidative kinetic resolution of secondary alcohols by hydrogen peroxide
Miao, Chengxia,Li, Xiao-Xi,Lee, Yong-Min,Xia, Chungu,Wang, Yong,Nam, Wonwoo,Sun, Wei
, p. 7476 - 7482 (2017/10/30)
The highly efficient catalytic oxidation and oxidative kinetic resolution (OKR) of secondary alcohols has been achieved using a synthetic manganese catalyst with low loading and hydrogen peroxide as an environmentally benign oxidant in the presence of a small amount of sulfuric acid as an additive. The product yields were high (up to 93%) for alcohol oxidation and the enantioselectivity was excellent (>90% ee) for the OKR of secondary alcohols. Mechanistic studies revealed that alcohol oxidation occurs via hydrogen atom (H-atom) abstraction from an α-CH bond of the alcohol substrate and a two-electron process by an electrophilic Mn-oxo species. Density functional theory calculations revealed the difference in reaction energy barriers for H-atom abstraction from the α-CH bonds of R- and S-enantiomers by a chiral high-valent manganese-oxo complex, supporting the experimental result from the OKR of secondary alcohols.
Direct conversion of allyl arenes to aryl ethylketones via a TBHP-mediated palladium-catalyzed tandem isomerization-Wacker oxidation of terminal alkenes
Zhao, Jinwu,Liu, Li,Xiang, Shijian,Liu, Qiang,Chen, Huoji
supporting information, p. 5613 - 5616 (2015/05/27)
A TBHP-mediated palladium-catalyzed tandem isomerization-Wacker oxidation of terminal alkenes was developed. This methodology provides a new efficient and simple route for conversion of a range of allyl arenes directly into aryl ethylketones in good yields with high chemoselectivity.
A chemoselective α-aminoxylation of aryl ketones: a cross dehydrogenative coupling reaction catalysed by Bu4NI
Siddaraju, Yogesh,Prabhu, Kandikere Ramaiah
supporting information, p. 11651 - 11656 (2015/12/08)
Tetrabutyl ammonium iodide (TBAI) catalyzed α-aminoxylation of ketones using aq. TBHP as an oxidant has been accomplished. We have shown that the CDC (cross dehydrogenative coupling) reactions of ketones with N-hydroxyimidates such as N-hydroxysuccinimide (NHSI), N-hydroxyphthalimide (NHPI), N-hydroxybenzotriazole (HOBt) and 1-hydroxy-7-azabenzotriazole (HOAt) lead to the corresponding oxygenated products in good to moderate yields. The application of this method has been demonstrated by transforming a few coupled products into synthetically useful intermediates and products.
Rhodium-catalyzed ketone methylation using methanol under mild conditions: Formation of α-branched products
Chan, Louis K. M.,Poole, Darren L.,Shen, Di,Healy, Mark P.,Donohoe, Timothy J.
supporting information, p. 761 - 765 (2014/01/23)
The rhodium-catalyzed methylation of ketones has been accomplished using methanol as the methylating agent and the hydrogen-borrowing method. The sequence is notable for the relatively low temperatures that are required and for the ability of the reaction system to form α-branched products with ease. Doubly alkylated ketones can be prepared from methyl ketones and two different alcohols by using a sequential one-pot iridium- and rhodium-catalyzed process. Uniquely effective for making branched alkyl products from ketones (see scheme): The scope of the presented reaction includes aromatic and aliphatic ketones and consecutive one-pot double alkylation reactions to provide a convenient route to branched ketones from simple methyl ketones. A brief study into the mechanism of the reaction has given evidence for an aldol-based reaction pathway.
Scalable synthetic route to 2-amino-5-hydroxypropiophenone: Efficient formal synthesis of irinotecan
Rao, A. V. Rama,Rao, Ramakrishna,Yadav,Khagga, Mukkanti
, p. 1661 - 1667 (2013/05/21)
2-Amino-5-hydroxypropiophenone, a key precursor in the total synthesis of irinotecan, has been synthesized. Regioselective nitration and a SNAr displacement are the key steps involved in this strategy, which is high yielding, is economical, and has been performed on a plant scale. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications1 to view the free supplemental file. Copyright Taylor & Francis Group, LLC.
Synthesis and antidepressant activity of arylalkanol-piperidine derivatives as triple reuptake inhibitors
Zheng, Yong-Yong,Guo, Lin,Zhen, Xue-Chu,Li, Jian-Qi
scheme or table, p. 123 - 136 (2012/09/08)
A series of arylalkanol-piperidine derivatives was synthesized, and their triple reuptake inhibition and in vivo activities have been evaluated. Among them, compounds 2a, 2j, 2k, 2m and 2n exhibited high potency for 5-HT, NA and DA transporters. Optimized compounds 2j and 2m showed significant reduction of immobility time compared to that of vehicle in the mouse tail suspension test (TST) test at doses ranging from 10 to 50 mg/kg po, and were not generally motor stimulants at 50 mg/kg dose. In addition, compounds 2j and 2m displayed desirable pharmacokinetic properties in SD rats.
Method of Synthesizing Key Intermediates for the Production of Camptothecin Derivatives
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Page/Page column 4, (2008/12/08)
The present invention discloses a process for efficient production of 2-amino-5-hydroxypropiophenone corresponding to the AB ring part of camptothecin (CPT) skeleton, which is a key intermediate useful for the total synthesis of camptothecin analogs including 7-Ethyl-10-hydroxy camptothecin and novel intermediates thereof.
Axially chiral NHC-Pd(II) complexes in the oxidative kinetic resolution of secondary alcohols using molecular oxygen as a terminal oxidant
Chen, Tao,Jiang, Jia-Jun,Xu, Qin,Shi, Min
, p. 865 - 868 (2007/10/03)
(Chemical Equation Presented) Axially chiral N-heterocyclic carbene (NHC) Pd(II) complexes were prepared from optically active 1,1′-binaphthalenyl- 2,2′-diamine (BINAM) and H8-BINAM and applied in the oxidative kinetic resolution of secondary alcohols using molecular oxygen as a terminal oxidant. The corresponding sec-alcohols can be obtained in good yields with moderate to good enantioselectivities.
METHOD OF SYNTHESIZING KEY INTERMEDIATES FOR THE PRODUCTION OF CAMPTOTHECIN DERIVATIVES
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Page/Page column 10, (2010/11/25)
The present invention discloses a process for efficient production of 2-amino-5- hydroxypropiophenone corresponding to the AB ring part of camptothecin (CPT) skelton, which is a key intermediate useful for the total synthesis of camptothecin analogs including 7-Ethyl-10-hydroxy camptothecin and novel intermediates thereof.
