27653-22-1Relevant articles and documents
Iron-Catalyzed Reductive Metalation-Allylation and Metalative Cyclization of 2,3-Disubstituted Oxetanes and Their Stereoselectivity
Sugiyama, Yu-Ki,Heigozono, Shiori,Tamura, Kazuhiro,Okamoto, Sentaro
, p. 2823 - 2828 (2016)
A novel process for the reductive magnesiation of 2-substituted oxetanes and the metalative cyclization of ω-alkynyl oxetanes is developed using n-propylmagnesium chloride in the presence of an iron catalyst. The generated intermediate organomagnesium compounds react with electrophiles. The reactions of 2,3-disubstituted oxetanes and their subsequent allylation with allyl halides in the presence or absence of copper(I) cyanide as the catalyst is studied with a unique switching of stereoselectivity being observed in the absence or presence of copper(I) cyanide. In addition, it is found that the metalative cyclization of 3-substituted 2-alkynyl oxetanes proceeds in an anti-selective manner starting from both syn- and anti-substrates. In all cases, the stereochemistry at the 2-position of the oxetanes is lost during the reactions suggesting the involvement of a radical process.
Epoxide Electroreduction
Huang, Cheng,Lu, Qingquan,Ma, Wan,Qi, Xiaotian,Xu, Minghao,Zheng, Xuelian
supporting information, p. 1389 - 1395 (2022/01/19)
Selective hydrogenation of epoxides would be a direct and powerful approach for alcohol synthesis, but it has proven to be elusive. Here, electrochemically epoxide hydrogenation using electrons and protons as reductants is reported. A wide range of primary, secondary, and tertiary alcohols can be achieved through selective Markovnikov or anti-Markovnikov ring opening in the absence of transition metals. Mechanistic investigations revealed that the regioselectivity is controlled by the thermodynamic stabilities of the in situ generated benzyl radicals for aryl-substituted epoxides and the kinetic tendency for Markovnikov selective ring opening for alkyl-substituted epoxides.
ANTICANCER 1,3-DIOXANE-4,6-DIONE DERIVATIVES AND METHOD OF COMBINATORIAL SYNTHESIS THEREOF
-
, (2020/12/14)
Compounds, methods of synthesis, and methods of cancer treatment by arylidene-1,3-dioxane-4,6-diones. A Meldrum's acid-based chemistry and hybrid solid-liquid method. The method includes protection of ketone and aldehyde components and simultaneous immobilization on the solid phase, introduction of substituents, grafts and derivatives compatible with the protection, detachment and restoration of active carbonyl reactivity, reaction of ketone library with malonate, reacting of the products with the aldehyde library in liquid phase and separation of the products by preparative HPLC.
Biocatalytic reduction of α,β-unsaturated carboxylic acids to allylic alcohols
Aleku, Godwin A.,Leys, David,Roberts, George W.
, p. 3927 - 3939 (2020/07/09)
We have developed robust in vivo and in vitro biocatalytic systems that enable reduction of α,β-unsaturated carboxylic acids to allylic alcohols and their saturated analogues. These compounds are prevalent scaffolds in many industrial chemicals and pharmaceuticals. A substrate profiling study of a carboxylic acid reductase (CAR) investigating unexplored substrate space, such as benzo-fused (hetero)aromatic carboxylic acids and α,β-unsaturated carboxylic acids, revealed broad substrate tolerance and provided information on the reactivity patterns of these substrates. E. coli cells expressing a heterologous CAR were employed as a multi-step hydrogenation catalyst to convert a variety of α,β-unsaturated carboxylic acids to the corresponding saturated primary alcohols, affording up to >99percent conversion. This was supported by the broad substrate scope of E. coli endogenous alcohol dehydrogenase (ADH), as well as the unexpected CC bond reducing activity of E. coli cells. In addition, a broad range of benzofused (hetero)aromatic carboxylic acids were converted to the corresponding primary alcohols by the recombinant E. coli cells. An alternative one-pot in vitro two-enzyme system, consisting of CAR and glucose dehydrogenase (GDH), demonstrates promiscuous carbonyl reductase activity of GDH towards a wide range of unsaturated aldehydes. Hence, coupling CAR with a GDH-driven NADP(H) recycling system provides access to a variety of (hetero)aromatic primary alcohols and allylic alcohols from the parent carboxylates, in up to >99percent conversion. To demonstrate the applicability of these systems in preparative synthesis, we performed 100 mg scale biotransformations for the preparation of indole-3-aldehyde and 3-(naphthalen-1-yl)propan-1-ol using the whole-cell system, and cinnamyl alcohol using the in vitro system, affording up to 85percent isolated yield.
Iridium Complex-Catalyzed C2-Extension of Primary Alcohols with Ethanol via a Hydrogen Autotransfer Reaction
Kobayashi, Masaki,Itoh, Satoshi,Yoshimura, Keisuke,Tsukamoto, Yuya,Obora, Yasushi
, p. 11952 - 11958 (2020/10/23)
The development of a C2-extension of primary alcohols with ethanol as the C2 source and catalysis by [Cp*IrCl2]2 (where Cp? = pentamethylcyclopentadiene) is described. This new extension system was used for a range of benzylic alcohol substrates and for aliphatic alcohols with ethanol as an alkyl reagent to generate the corresponding C2-extended linear alcohols. Mechanistic studies of the reaction by means of intermediates and deuterium labeling experiments suggest the reaction is based on hydrogen autotransfer.
Palladium(II)-Catalyzed Enantioselective Arylation of Unbiased Methylene C(sp3)?H Bonds Enabled by a 2-Pyridinylisopropyl Auxiliary and Chiral Phosphoric Acids
Yan, Sheng-Yi,Han, Ye-Qiang,Yao, Qi-Jun,Nie, Xing-Liang,Liu, Lei,Shi, Bing-Feng
supporting information, p. 9093 - 9097 (2018/07/25)
Enantioselective functionalizations of unbiased methylene C(sp3)?H bonds of linear systems by metal insertion are intrinsically challenging and remain a largely unsolved problem. Herein, we report a palladium(II)-catalyzed enantioselective arylation of unbiased methylene β-C(sp3)?H bonds enabled by the combination of a strongly coordinating bidentate PIP auxiliary with a monodentate chiral phosphoric acid (CPA). The synergistic effect between the PIP auxiliary and the non-C2-symmetric CPA is crucial for effective stereocontrol. A broad range of aliphatic carboxylic acids and aryl bromides can be used, providing β-arylated aliphatic carboxylic acid derivatives in high yields (up to 96 %) with good enantioselectivities (up to 95:5 e.r.). Notably, this reaction also represents the first palladium(II)-catalyzed enantioselective C?H activation with less reactive and cost-effective aryl bromides as the arylating reagents. Mechanistic studies suggest that a single CPA is involved in the stereodetermining C?H palladation step.
Practical Intermolecular Hydroarylation of Diverse Alkenes via Reductive Heck Coupling
Gurak, John A.,Engle, Keary M.
, p. 8987 - 8992 (2018/09/11)
The hydroarylation of alkenes is an attractive approach to construct carbon-carbon (C-C) bonds from abundant and structurally diverse starting materials. Herein we report a palladium-catalyzed reductive Heck hydroarylation of aliphatic and heteroatom-substituted terminal alkenes and select internal alkenes with an array of (hetero)aryl iodides. The reaction is anti-Markovnikov selective with terminal alkenes and tolerates a wide variety of functional groups on both the alkene and (hetero)aryl coupling partners. Additionally, applications of this method to complex molecule diversifications are demonstrated. Mechanistic experiments are consistent with a mechanism in which the key alkylpalladium(II) intermediate is intercepted with formate and undergoes a decarboxylation/C-H reductive elimination cascade to afford the saturated product and turn over the cycle.
Synthesis of 2-tetralone derivatives by Bi(OTf)3-catalyzed intramolecular hydroarylation/isomerization of propargyl alcohols
Yun, Jihee,Park, Jungmin,Kim, Jaehyun,Lee, Kooyeon
, p. 1045 - 1048 (2015/02/19)
Compared to 1-tetralones, 2-tetralones are expensive, less stable, and difficult to synthesize. A concise Bi-catalyzed method was developed for the synthesis of 2-tetralones from 5-phenylpent-1-yn-3-ol derivatives. Diverse 2-tetralones were obtained in moderate to good yields under mild conditions.
Synthesis and evaluation of 4-substituted piperidines and piperazines as balanced affinity μ opioid receptor (MOR) agonist/δ opioid receptor (DOR) antagonist ligands
Bender, Aaron M.,Clark, Mary J.,Agius, Michael P.,Traynor, John R.,Mosberg, Henry I.
, p. 548 - 551 (2014/01/23)
In this letter, we describe a series of 4-substituted piperidine and piperazine compounds based on tetrahydroquinoline 1, a compound that shows balanced, low nanomolar binding affinity for the mu opioid receptor (MOR) and the delta opioid receptor (DOR).
Effective and reversible DNA condensation induced by bifunctional molecules containing macrocyclic polyamines and naphthyl moieties
Yan, Hao,Li, Zhi-Fen,Guo, Zhi-Fo,Lu, Zhong-Lin,Wang, Feng,Wu, Li-Zhu
supporting information; experimental part, p. 801 - 808 (2012/03/26)
A series of bifunctional molecules containing macrocyclic polyamines [12]aneN3 and naphthyl moieties 1-3(a, b) have been designed and synthesized through efficient N-alkylation and copper-mediated alkyne-azide click reactions. Experiments on gel electrophoresis, dynamic light scattering and atomic force microscopy confirmed that 2b and 3b with two [12]aneN 3 units efficiently induced the DNA condensation at the concentration of 120 μM in less than 5 min. The condensation mechanism was studied by EB displacement fluorescence spectra, viscosity titration, and ionic strength effects. The condensation process was found to be reversible, and the presence of both naphthyl and [12]aneN3 units in the molecules was proved to be necessary for the effective DNA condensation inductions. Cytotoxicity assay showed that the presence of triazole moieties can result in lower toxicity.
