- Diazaphosphinyl radical-catalyzed deoxygenation of α-carboxy ketones: A new protocol for chemo-selective C-O bond scission: Via mechanism regulation
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C-O bond cleavage is often a key process in defunctionalization of organic compounds as well as in degradation of natural polymers. However, it seldom occurs regioselectively for different types of C-O bonds under metal-free mild conditions. Here we report a facile chemo-selective cleavage of the α-C-O bonds in α-carboxy ketones by commercially available pinacolborane under the catalysis of diazaphosphinane based on a mechanism switch strategy. This new reaction features high efficiency, low cost and good group-tolerance, and is also amenable to catalytic deprotection of desyl-protected carboxylic acids and amino acids. Mechanistic studies indicated an electron-transfer-initiated radical process, underlining two crucial steps: (1) the initiator azodiisobutyronitrile switches originally hydridic reduction to kinetically more accessible electron reduction; and (2) the catalytic phosphorus species upconverts weakly reducing pinacolborane into strongly reducing diazaphosphinane. This journal is
- Cheng, Jin-Pei,Yang, Jin-Dong,Zhang, Jingjing
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p. 8476 - 8481
(2020/09/07)
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- 2,2-Diazido-1,2-diarylethanones: Synthesis and Reactivity with Primary Amines
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We describe the synthesis and reactivity of a new class of diazidated compounds: the 2,2-diazido-1,2-diarylethanones. The diazides are easily accessible from 1,2-diarylethanones through a mild and simple protocol for the direct oxidative diazidation, using iodine and sodium azide in DMSO at room temperature. In studies towards their reactivity with amine nucleophiles under basic conditions, the diazides are shown to undergo a controlled fragmentation reaction that provides a straightforward access to the corresponding amides. In stark contrast to our previous results on the amine-triggered fragmentation of diazidated compounds, aromatic nitriles are found to be by-products of synthetic value. The net reaction consisting of diazidation and subsequent fragmentation, thus, provides a simple way to convert 1,2-diarylethanones into both aromatic amides and nitriles.
- Holzschneider, Kristina,H?ring, Andreas P.,Kirsch, Stefan F.
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p. 2824 - 2831
(2019/04/30)
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- Method for preparing diphenylethanone from benzyl alcohol through photocatalytic one-step method
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The present invention relates to a method for preparing diphenylethanone from benzyl alcohol through a photocatalytic one-step method. According to the method, diphenylethanone is directly prepared byusing inexpensive benzyl alcohol as a raw material under the action of a solid photocatalyst; and the reaction process comprises: mixing benzyl alcohol, a catalyst and an acetonitrile solvent are mixed, placing in a pressure container, replacing with an inert gas, and carrying out illumination stirring at a room temperature, wherein the reaction time is more than 1 h, the catalyst is easily separated from the reaction system after the reaction and can be recycled multiple times, and the separation yield of diphenylethanone is up to 81%.
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Paragraph 0039; 0040
(2018/09/13)
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- Facile Access to Multiaryl-1H-pyrrol-2(3H)-ones by Copper/TEMPO-Mediated Cascade Annulation of Diarylethanones with Primary Amines and Mechanistic Insight
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A straightforward approach to an array of multiaryl-1H-pyrrol-2(3H)-ones featuring an α-diarylated all-carbon quaternary center was developed by using diarylethanones and primary amines as the raw materials. A complete mechanism involving a CuO/TEMPO-mediated multistep cascade process with an inherent delicate balance of substituent electronic effect is proposed. Moreover, this class of multiaryl β,γ-unsaturated γ-lactams demonstrates an intriguing aggregation-induced emission effect valuable for potential application in developing luminescent materials.
- Wang, Xing,Zhang, Chen-Yang,Tu, Hai-Yang,Zhang, Ai-Dong
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supporting information
p. 5243 - 5247
(2016/11/13)
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- Selective reduction of carbonyl groups in the presence of low-valent titanium reagents
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The chemoselective reduction of several structurally diverse compounds containing carbonyl groups was achieved in the presence of low-valent titanium reagents. This novel synthetic method provides easy access to highly selective reduction of carbonyl groups, and possesses several advantages including one-step procedure, convenient manipulation, good to excellent yields, and short reaction times.
- Lin, Wei,Hu, Ming-Hua,Feng, Xian,Fu, Lei,Cao, Cheng-Pao,Huang, Zhi-Bin,Shi, Da-Qing
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p. 2238 - 2242
(2014/04/17)
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- Structure-based design and synthesis of antiparasitic pyrrolopyrimidines targeting pteridine reductase 1
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The treatment of Human African trypanosomiasis remains a major unmet health need in sub-Saharan Africa. Approaches involving new molecular targets are important; pteridine reductase 1 (PTR1), an enzyme that reduces dihydrobiopterin in Trypanosoma spp., has been identified as a candidate target, and it has been shown previously that substituted pyrrolo[2,3-d]pyrimidines are inhibitors of PTR1 from Trypanosoma brucei (J. Med. Chem. 2010, 53, 221-229). In this study, 61 new pyrrolo[2,3-d]pyrimidines have been prepared, designed with input from new crystal structures of 23 of these compounds complexed with PTR1, and evaluated in screens for enzyme inhibitory activity against PTR1 and in vitro antitrypanosomal activity. Eight compounds were sufficiently active in both screens to take forward to in vivo evaluation. Thus, although evidence for trypanocidal activity in a stage I disease model in mice was obtained, the compounds were too toxic to mice for further development.
- Khalaf, Abedawn I.,Huggan, Judith K.,Suckling, Colin J.,Gibson, Colin L.,Stewart, Kirsten,Giordani, Federica,Barrett, Michael P.,Wong, Pui Ee,Barrack, Keri L.,Hunter, William N.
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supporting information
p. 6479 - 6494
(2014/10/16)
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- HETEROCYCLIC COMPOUNDS FOR THE INHIBITION OF PASK
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Disclosed herein are new heterocyclic compounds of Formula IIa: and compositions thereof, and their application as pharmaceuticals for the treatment of disease. Methods of inhibiting PAS Kinase (PASK) activity in a human or animal subject are also provided for the treatment of diseases such as diabetes mellitus.
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- Exploration of the SAR of anti-invasive chalcones: Synthesis and biological evaluation of conformationally restricted analogues
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In order to get a clearer view on the active geometry of anti-invasive chalcones, we have prepared a number of isoxazoles and related substances as conformationally restrained mimics of 1,3-diarylpropenones, and also of (Z)-stilbenes. In vitro anti-invasi
- Roman, Bart I.,Ryck, Tine De,Dierickx, Laura,Vanhoecke, Barbara W.A.,Katritzky, Alan R.,Bracke, Marc,Stevens, Christian V.
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p. 4812 - 4819
(2012/09/08)
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- Discovery of novel and potent heterocyclic carboxylic acid derivatives as protein tyrosine phosphatase 1B inhibitors
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A series of novel heterocyclic carboxylic acid based protein tyrosine phosphatase 1B (PTP1B) inhibitors with hydrophobic tail have been synthesized and characterized. Structure-activity relationship (SAR) optimization resulted in identification of several
- Basu, Sujay,Prasad, Uppuleti Viplava,Barawkar, Dinesh A.,De, Siddhartha,Palle, Venkata P.,Menon, Suraj,Patel, Meena,Thorat, Sachin,Singh, Umesh P.,Sarma, Koushik Das,Waman, Yogesh,Niranjan, Sanjay,Pathade, Vishal,Gaur, Ashwani,Reddy, Satyanarayana,Ansari, Shariq
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p. 2843 - 2849
(2012/05/20)
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- Metal-free reductive cleavage of C-O σ-bonds in acyloin derivatives by an organic neutral super-electron-donor
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(Chemical Equation Presented) Neutral organic electron-donor 7, formally a pyridinylidene carbene dimer, effects reductive cleavage of C-O σ-bonds in acyloin derivatives Ar(CO)CRR′OX (X = OAc, OPiv, OBz, OMs) and this represents the first cleavage of C-O σ-bonds by a neutral organic electron-donor. The methodology is applicable to a large array of substrates and the reduced counterparts were isolated in good to excellent yields. For certain substrates, donor 7 behaves as a base, effecting condensation reactions with some acetate ester derivatives of acyloins, leading to butenolides. The variation in reactivity among the different substrates was rationalized. 2009 American Chemical Society.
- Cutulic, Sylvain P. Y.,Findlay, Neil J.,Zhou, Sheng-Ze,Chrystal, Ewan J. T.,Murphy, John A.
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supporting information; experimental part
p. 8713 - 8718
(2009/12/28)
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- Synthesis and SAR of 2,3-diarylpyrrole inhibitors of parasite cGMP-dependent protein kinase as novel anticoccidial agents
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Several analogs of 2,3-diaryl pyrroles were synthesized and evaluated as inhibitors of Eimeria tenella cGMP-dependent protein kinase and in in vivo anticoccidial assays. A 4-fluorophenyl group enhances both in vitro and in vivo activities. The most potent
- Biftu, Tesfaye,Feng, Dennis,Ponpipom, Mitree,Girotra, Narindar,Liang, Gui-Bai,Qian, Xiaoxia,Bugianesi, Robert,Simeone, Joseph,Chang, Linda,Gurnett, Anne,Liberator, Paul,Dulski, Paula,Leavitt, Penny Sue,Crumley, Tami,Misura, Andrew,Murphy, Terence,Rattray, Sandra,Samaras, Samantha,Tamas, Tamas,Mathew, John,Brown, Christine,Thompson, Don,Schmatz, Dennis,Fisher, Michael,Wyvratt, Matthew
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p. 3296 - 3301
(2007/10/03)
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- Reactions of aroyl chlorides with samarium metal in DMF-controllable syntheses of O-aroylbenzoins, 1,2-diarylethanones, and (z)-α, α′-stilbenediol dibenzoates
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Reduction of aroyl chlorides carried out in DMF with samarium metal has been studied. Samarium metal, which requires not any intended activation or pretreatment, was found to react with aroyl chloride in a controllable manner. Correspondingly, O-aroylbenzoins, 1,2-diarylethanones, or (Z)-α, α′-stilbenediol dibenzoates were afforded as the major products under controlled conditions.
- Liu, Yongjun,Wang, Xiaoxia,Zhang, Yongmin
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p. 4009 - 4022
(2007/10/03)
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- 10,5-(Iminomethano)-10,11-dihydro-5H-dibenzo[a,d]cycloheptene and derivatives. Potent PCP receptor ligands
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IDDC (3, 10,5-(iminomethano)-10,11-dihydro-5H-dibenzo[a,d]cycloheptene) and a series of substituted derivatives were synthesized and evaluated in vitro for their ability to displace tritiated MK-801 ([3H]-2) from its specific binding site in guinea pig brain homogenate. Substitution at the 3- position of 3 with bromine, chlorine, and fluorine led to increased binding affinity. In contrast, substitution of donor groups at the 3-position gave decreased binding affinities, as did all substitutions at the 7-position and on nitrogen. Where racemic mixtures were resolved, the (+)-optical antipodes were more active than their enantiomers or racemates. The most active ligand found in this study was (+)-13e (IC50 = 15.5 ± 4.5 nM). The affinity of (+)-13e for the PCP receptor makes it among the most potent ligands known. In vitro neuroprotection was demonstrated by 3, (+)-3, and (+)-6 (N-Me-IDDC) against glutamate-induced cell death in rat hippocampal cells.
- Gee,Barmettler,Rhodes,McBurney,Reddy,Hu -,Cotter,Hamilton,Weber,Keana
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p. 1938 - 1946
(2007/10/02)
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- Pyridazine 3,5-dihydroxy carboxylic acids and derivatives thereof, the use thereof for hypercholesterolemia
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New 3,5-dihydroxy carboxylic acids and derivatives thereof, a process for the preparation thereof, the use thereof as pharmaceuticals, pharmaceutical products and intermediates 3,5-Dihydroxy carboxylic acids and derivatives thereof, of the formula I STR1
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- IODOTRIMETHYLSILANE REDUCTION OF BENZOINS: SYNTHESIS OF DEOXYBENZOINS AND TETRAARYLFURANS
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Benzoins react readily with idotriethylsilane to produce, in many cases, mixtures of deoxybenzoins and tetraarylfurans.
- Krepski, Larry R.,Heilmann, Steven M.,Rasmussen, Jerald K.,Tumey, Michael L.,Smith, Howell K.
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p. 377 - 386
(2007/10/02)
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