827-92-9Relevant academic research and scientific papers
Electrochemistry Broadens the Scope of Flavin Photocatalysis: Photoelectrocatalytic Oxidation of Unactivated Alcohols
Zhang, Wen,Carpenter, Keith L.,Lin, Song
supporting information, p. 409 - 417 (2019/11/25)
Riboflavin-derived photocatalysts have been extensively studied in the context of alcohol oxidation. However, to date, the scope of this catalytic methodology has been limited to benzyl alcohols. In this work, mechanistic understanding of flavin-catalyzed oxidation reactions, in either the absence or presence of thiourea as a cocatalyst, was obtained. The mechanistic insights enabled development of an electrochemically driven photochemical oxidation of primary and secondary aliphatic alcohols using a pair of flavin and dialkylthiourea catalysts. Electrochemistry makes it possible to avoid using O2 and an oxidant and generating H2O2 as a byproduct, both of which oxidatively degrade thiourea under the reaction conditions. This modification unlocks a new mechanistic pathway in which the oxidation of unactivated alcohols is achieved by thiyl radical mediated hydrogen-atom abstraction.
Synthesis of Branched Tryptamines via the Domino Cloke-Stevens/Grandberg Rearrangement
Salikov, Rinat F.,Trainov, Konstantin P.,Levina, Anastasia A.,Belousova, Irina K.,Medvedev, Michael G.,Tomilov, Yury V.
, p. 790 - 795 (2017/04/26)
The rearrangement of cyclopropylketone arylhydrazones generated in situ from arylhydrazine hydrochlorides and ketones leads to formation of tryptamine derivatives. The use of (2-arylcyclopropyl)ethanones in the reactions with model 4-bromophenylhydrazine hydrochloride gives branched tryptamines with aryl groups in the α-position to the amino group, while (2-methylcyclopropyl)ethanone gives a mixture of α- and β-substituted products in a ratio of 1:3. The method was found effective in the synthesis of enantiomerically pure tryptamine. Thus, (R,R)-(2-phenylcyclopropyl)ethanone gives the (S)-α-phenyltryptamine derivative with an enantiomeric excess over 99%.
TETRAZOLINONE COMPOUND AND USE THEREOF
-
Paragraph 0847; 0917, (2015/11/16)
The compound represented by formula (1): wherein R4 and R5 each represents a hydrogen atom, a halogen atom, or a C1-C3 alkyl group; R6 represents a C1-C4 alkyl group, a C3-C6 cycloalkyl group, or the like; R7, R8, and R9 each represents a hydrogen atom, a halogen atom, or the like; R10 represents a C1-C3 alkyl group, or the like; R13 represents a C1-C3 alkyl group, or the like; and Q represents a phenyl group, or the like; has an excellent control effect on pests.
Conformational restriction approach to β-secretase (BACE1) inhibitors III: Effective investigation of the binding mode by combinational use of X-ray analysis, isothermal titration calorimetry and theoretical calculations
Yonezawa, Shuji,Fujiwara, Kenichiro,Yamamoto, Takahiko,Hattori, Kazunari,Yamakawa, Hidekuni,Muto, Chie,Hosono, Motoko,Tanaka, Yoshikazu,Nakano, Toru,Takemoto, Hiroshi,Arisawa, Mitsuhiro,Shuto, Satoshi
, p. 6506 - 6522 (2013/10/22)
For further investigation of BACE1 inhibitors using conformational restriction with sp3 hybridized carbon, we applied this approach to 6-substituted aminopyrimidone derivatives 3 to improve the inhibitory activity by reducing the entropic energy loss upon binding to BACE1. Among eight stereoisomers synthesized, [trans-(1′R,2′R),6S] isomer 6 exhibited the best BACE1 inhibitory activity, which was statistically superior to that of the corresponding ethylene linker compound (R)-3. Combinational examinations of the binding mode of 6 were performed, which included isothermal titration calorimetry (ITC), X-ray crystallographic structure analysis and theoretical calculations, to clarify the effect of our conformational restriction approach. From the ITC measurement, the binding entropy of 6 was found to be ~0.5 kcal larger than that of (R)-3, which is considered to be affected by conformational restriction with a cyclopropane ring.
Improved dimethylsulfoxonium methylide cyclopropanation procedures, including a tandem oxidation variant
Paxton, Richard J.,Taylor, Richard J. K.
, p. 633 - 637 (2007/10/03)
A new procedure for the cyclopropanation of α,β-unsaturated carbonyl compounds and related systems is described which employs trimethylsulfoxonium iodide and an organic base in acetonitile to generate dimethylsulfoxonium methylide in situ; in addition, pr
Thienopyridones as AMPK activators for the treatment of diabetes and obesity
-
Page/Page column 51, (2010/02/10)
The present invention relates to compounds that activate AMP-activated protein kinase (AMPK), including the preparation of the compounds, compositions containing the compounds and the use of the compounds in the prevention or treatment of disorders such as diabetes, metabolic syndrome, and obesity.
Novel synthesis of substituted cyclopropane acetic acid ethyl esters from cyclopropyl alkyl ketones
Nongkhlaw, Rishan Lang,Nongrum, Ridaphun,Nongkynrih, Irona,Vattakunnel, Felix Mathew,Myrboh, Bekington
, p. 1054 - 1057 (2007/10/03)
The cyclopropane acetic acid ethyl esters 2 have been conveniently prepared in one step from cyclopropyl alkyl ketones 1 by reacting with lead (IV) acetate in triethyl orthoformate in the presence of 70% perchloric acid. In all these reactions triethyl or
Hypersensitive radical probe studies of chloroperoxidase-catalyzed hydroxylation reactions
Toy, Patrick H.,Newcomb, Martin,Hager, Lowell P.
, p. 816 - 823 (2007/10/03)
The oxidation of hypersensitive radical probes by chloroperoxidase from Caldariomyces fumago (CPO) was studied in an attempt to 'time' a putative radical intermediate. Oxidation of (trans-2-phenylcyclopropyl)methane, previously studied by Zaks and Dodds [Zaks, A., and Dodds, D. R. (1995) J. Am. Chem. Soc. 115, 10419-10424] was reinvestigated. Unrearranged oxidation products were found as previously reported, and control experiments demonstrated that the cyclic alcohol from oxidation at the cyclopropylcarbinyl position, while subject to further oxidation, survives CPO oxidation as detectable species. However, in contrast to the report by Zaks and Dodds, the rearranged alcohol product expected from ring opening of a cyclopropylcarbinyl radical intermediate was shown to be unstable toward the enzyme oxidation reaction. Because of this instability, two new hypersensitive radical probes, (trans-2-phenylcyclopropyl)ethane and 2- (trans-2-phenylcyclopropyl)propane, and their potential cyclic and acyclic products from oxidation at the cyclopropylcarbinyl position were synthesized and tested. Oxidation of both of these probes at the cyclopropylcarbinyl position by CPO gave unrearranged alcohol products only, but control experiments again demonstrated that the rearranged alcohol products were unstable toward CPO oxidation conditions. From the combination of the probe and control studies, the lifetime of a putative radical intermediate must be less than 3 ps. Whereas the results are consistent with an insertion mechanism for production of alcohol product, they do not exclude a very short-lived intermediate.
Enantioselective Cyclopropanation of Allylic Alcohols. The Effect of Zinc Iodide
Denmark, Scott E.,O'Connor, Stephen P.
, p. 3375 - 3389 (2007/10/03)
The effect of zinc iodide on the catalytic, enantioselective cyclopropanation of aliylic alcohols is examined with bis(iodomethyl)zinc as the reagent and bis-methanesulfonamide 7 as the catalyst. Significant rate enhancement was observed when 1 equiv of zinc iodide was present, but more importantly, the enantiomeric excess of the product cyclopropane increased from 80% to 89% for the substrate cinnamyl alcohol. Reaction studies and spectroscopic investigations show that this remarkable influence is the result of reagent modification via a Schlenk equilibrium that produces the more reactive and selective species (iodomethyl)zinc iodide.
Reaction of acylsilanes with sulfur ylides. Selective formation of silyl enol ethers or β-ketosilanes
Nakajima, Tadashi,Segi, Masahito,Sugimoto, Fumitosi,Hioki, Reiko,Yokota, Seiko,Miyashita, Kiyoshi
, p. 8343 - 8358 (2007/10/02)
The reaction of acylsilanes with sulfur ylides in THF results in the formation of the corresponding silyl enol ethers or β-ketosilanes. The relative ratio of these products varies with the ylide conditions and the stability of ylide used. It is noteworthy that silyl enol ethers were formed under the salt-free ylide conditions, and that β-ketosilanes were yielded in the presence of soluble inorganic salts in THF, selectively. The formation of both products would be interpreted in terms of the anionotropic and cationotropic rearrangements of silyl group in the reaction intermediate.
