- Tunable System for Electrochemical Reduction of Ketones and Phthalimides
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Herein, we report an efficient, tunable system for electrochemical reduction of ketones and phthalimides at room temperature without the need for stoichiometric external reductants. By utilizing NaN3 as the electrolyte and graphite felt as both the cathode and the anode, we were able to selectively reduce the carbonyl groups of the substrates to alcohols, pinacols, or methylene groups by judiciously choosing the solvent and an acidic additive. The reaction conditions were compatible with a diverse array of functional groups, and phthalimides could undergo one-pot reductive cyclization to afford products with indolizidine scaffolds. Mechanistic studies showed that the reactions involved electron, proton, and hydrogen atom transfers. Importantly, an N3/HN3 cycle operated as a hydrogen atom shuttle, which was critical for reduction of the carbonyl groups to methylene groups.
- Chen, Gong,Qiao, Tianjiao,Wang, Yaxin,Zhang, Jian,Zhao, Jianyou
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supporting information
p. 3297 - 3302
(2021/10/14)
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- I2/Li2CO3-promoted cyanation of diarylalcohols through a dual activation process
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One-step base promoted strategy for cyanation of α,α-diaryl alcohols has been developed under mild and transition metal-free conditions. This method provides a straightforward and facile way towards the synthesis of β,γ-unsaturated nitriles and α-phenylnitiriles from α-vinyl carbinols and α,α-diaryl methanols, respectively, up to 99% yield. Moreover, various azides and ethers could also be accessed from their respective nucleophiles under standard reaction conditions.
- Hu, Liangzhen,Hussain, Muhammad Ijaz,Deng, Qingfu,Liu, Qing,Feng, Yangyang,Zhang, Xiaohui,Xiong, Yan
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p. 308 - 314
(2018/12/11)
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- One-pot synthesis of indene derivatives by CF3SO 3H-promoted reactions of benzylic alcohols and 1,3-dicarbonyl compounds
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An efficient and convenient one-pot synthesis of indene derivatives was achieved in moderate to high yields by the CF3SO3H promoted coupling/cyclization reaction of benzylic alcohols and 1,3-dicarbonyls for the first time. For the reactions of methoxy- or methyl-substituted diarylmethanols with 1,3-dicarbonyls, 2 equiv of CF3SO3H was needed to reach the best results; but for the reactions of methoxy-substituted arylethanols with 1,3-dicarbonyls, 0.6 equiv of CF 3SO3H at lower temperatures was capable of promoting the reaction finished.
- Zhang, Wei,Zhang, Wenxue,Dai, Yisi,Zhu, Haizhen
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supporting information
p. 1747 - 1750
(2013/03/28)
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- Direct electrosynthesis of ketones from benzylic methylenes by electrooxidative C-H activation
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Electrify your chemistry! Direct electrosynthesis of ketones from benzylic methylenes in an undivided cell was realized in moderate to good yields (see scheme). In this electrosynthesis, electrons instead of conventional oxidants and catalysts are employed to make the reaction environmentally benign. Moreover, the reaction intermediate radical was detected by ESR spectroscopy and the reaction mechanism was clarified.
- Meng, Li,Su, Jihu,Zha, Zhenggen,Zhang, Li,Zhang, Zhenlei,Wang, Zhiyong
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supporting information
p. 5542 - 5545
(2013/05/23)
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- Synthesis, antibacterial and antifungal activities of bifonazole derivatives
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Two series of chlorinated benzhydryl imidazole and triazole derivatives were synthesized and tested in vitro against representative strains of potent pathogenic bacteria (Staphylococcus aureus CIP 4.83, Escherichia hirae CIP 5855, Pseudomonas aeruginosa CIP 82118, Escherichia coli CIP 53126) and fungi (Aspergillus niger IP 1431.83, Candida albicans IP 48.72, Candida krusei IP 208.52, Trichophython rubrum IP 1657.86). Most of these compounds were devoid of any antimicrobial activity, but several of them inhibited T. rubrum with MIC values in the range of 0.125 to 32 μg/mL, similar or superior to those of bifonazole and clotrimazole, used as standard controls. The replacement of the imidazole ring with a triazole moiety in these compounds led to derivatives with less antifungal activity. A preliminary SAR was undertaken on the effect of the number and the position of chlorine atoms on the distribution of negative charge on the surface of some compounds on antifungal activity. Copyright
- El Hage, Salome,Lajoie, Barbora,Feuillolay, Catherine,Roques, Christine,Baziard, Genevieve
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experimental part
p. 402 - 410
(2012/01/11)
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- Microwave-assisted nickel(II) acetylacetonate-catalyzed arylation of aldehydes with arylboronic acids
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Applying sealed vessel microwave heating at 180 °C in toluene the arylation of aromatic and aliphatic aldehydes with arylboronic acids using 1-2 mol % of Ni(acac)2 as a catalyst can be performed efficiently within 10-30 min providing the desired diarylmethanols or benzyl alcohols in good yields.
- Chen, Wen,Baghbanzadeh, Mostafa,Kappe, C. Oliver
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experimental part
p. 1677 - 1679
(2011/04/25)
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- Structure-activity relationships of diphenylpiperazine N-type calcium channel inhibitors
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A novel series of compounds derived from the previously reported N-type calcium channel blocker NP118809 (1-(4-benzhydrylpiperazin-1-yl)-3,3-diphenylpropan-1-one) is described. Extensive SAR studies resulted in compounds with IC50 values in the range of 10-150 nM and selectivity over the L-type channels up to nearly 1200-fold. Orally administered compounds 5 and 21 exhibited both anti-allodynic and anti-hyperalgesic activity in the spinal nerve ligation model of neuropathic pain.
- Pajouhesh, Hassan,Feng, Zhong-Ping,Ding, Yanbing,Zhang, Lingyun,Pajouhesh, Hossein,Morrison, Jerrie-Lynn,Belardetti, Francesco,Tringham, Elizabeth,Simonson, Eric,Vanderah, Todd W.,Porreca, Frank,Zamponi, Gerald W.,Mitscher, Lester A.,Snutch, Terrance P.
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scheme or table
p. 1378 - 1383
(2010/07/06)
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- Ni(COD)2/4-ClC6H4COR-catalyzed addition reactions of arylboroxines with aldehydes
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Ni(COD)2/4-ClC6H4COR (R = H, CH3, Ph) was found to be an efficient catalyst system for the addition reactions of arylboroxines with aromatic and aliphatic aldehydes. The catalytically active species for Ni(COD)2/4-ClC6H4COR catalyst systems was likely to be their oxidative addition adducts, 4-RCOC6H4Ni(II)Cl(COD) complexes.
- Xing, Chun-Hui,Hu, Qiao-Sheng
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supporting information; experimental part
p. 924 - 927
(2010/05/18)
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- A metal-free catalytic system for the oxidation of benzylic methylenes and primary amines under solvent-free conditions
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Iodine-pyridine-tert-butylhydroperoxide is developed as a green and efficient catalytic system for the oxidation of benzylic methylenes to ketones and primary amines to nitriles. The reaction conditions are quite mild and environmentally benign, no transition metals, organic solvents or hazard reagents being needed. The oxidation of benzylic methylenes gave the corresponding ketones in excellent yields with complete chemoselectivity, while the oxidation of primary amines was complete in several minutes, affording various nitriles in moderate to good yields.
- Zhang, Jintang,Wang, Zhentao,Wang, Ye,Wan, Changfeng,Zheng, Xiaoqi,Wang, Zhiyong
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supporting information; scheme or table
p. 1973 - 1978
(2010/06/15)
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- Copper-catalyzed synthesis of enantioenriched tetraarylethanes
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Herein we report the asymmetric synthesis of 1,2-dipyridyl-1,2- diarylethanes via an unusual Cu(l)-catalyzed dimerization reaction. Subjection of a variety of enantioenriched substituted 2-pyridyl alcohols to a one-pot protocol generates the desired products in good yields and diastereoselectivities and with ee's up to >99%.
- Jen, Wendy S.,Truppo, Matthew D.,Amos, Deborah,Devine, Paul,McNevin, Michael,Biba, Mirlinda,Campos, Kevin R.
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supporting information; experimental part
p. 741 - 744
(2009/04/06)
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- Kinetics of the solvolyses of benzhydryl derivatives: Basis for the construction of a comprehensive nucleofugality scale
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A series of 21 benzhydrylium ions (diarylmethylium ions) are proposed as reference electrofuges for the development of a general nucleofugality scale, where nucleofugality refers to a combination of leaving group and solvent. A total of 167 solvolysis rate constants of benzhydrylium tosylates, bromides, chlorides, trifluoroacetates, 3,5-dinitrobenzoates, and 4-nitroben-zoates, two-thirds of which have been determined during this work, were subjected to a least-squares fit according to the correlation equation log k 25°C = Sf(Nf + Ef), where s f and Nf are nucleofuge-specific parameters and E f is an electrofuge-specific parameter. Although nucleofuges and electrofuges characterized in this way cover more than 12 orders of magnitude, a single set of the parameters, namely sf, Nf, and E f, is sufficient to calculate the solvolysis rate constants at 25°C with an accuracy of ± 16%. Because sf ≈ 1 for all nucleofuges, that is, leaving group/ solvent combinations, studied so far, qualitative discussions of nucleofugality can be based on Nf.
- Denegri, Bernard,Streiter, Andre,Juric, Sandra,Ofial, Armin R.,Kronja, Olga,Mayr, Herbert
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p. 1648 - 1656
(2007/10/03)
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- BENZENE DERIVATIVES,PROCESS FOR PREPARING THE SAME AND USE THEREOF
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Novel benzene derivatives represented by the formula (I) : wherein R1, R4 and R6 each independently represents a hydrogen atom, a halogen atom or a hydrocarbon group, R2 represents a hydrocarbon group or a heterocyclic group, R3 represents a hydrocarbon group, NR7'R7 or OR8 (wherein R7' represents a hydrogen atom or a hydrocarbon group, R7 represents a non-aromatic group, or R7' and R7 may form a ring with the adjacent nitrogen atom, and R8 represents a hydrocarbon group or a heterocyclic group), R5 represents a hydrocarbon group or a heterocyclic group (except for a quinolyl group), R5' represents a hydrogen atom, or a hydrocarbon group, or R5 and R5' may form a ring with the adjacent nitrogen atom, and R5" represents a hydrogen atom or a hydrocarbon group, which have vanilloid receptor agonist activity and are useful as a drug such as an analgesic and an agent for preventing and/or treating urinary frequency and/or urinary incontinence.
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- Selective hydrogenation of benzophenones to benzhydrols. Asymmetric synthesis of unsymmetrical diarylmethanols
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(Graph presented) trans-RuCl2[P(C6H4-4-CH3) 3]2(NH2CH2CH2NH 2) acts as a highly effective precatalyst for the hydrogenation of a variety of benzophenone derivatives to benzhydrols that proceeds smoothly at 8 atm and 23-35 °C in 2-propanol containing t-C4H9OK with a substrate/catalyst ratio of 2000-20000. Use of a BINAP/chiral diamine Ru complex effects asymmetric hydrogenation of various ortho-substituted benzophenones and benzoylferrocene to chiral diarylmethanols with consistently high ee.
- Ohkuma, Takeshi,Koizumi, Masatoshi,Ikehira, Hideyuki,Yokozawa, Tohru,Noyori, Ryoji
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p. 659 - 661
(2007/10/03)
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- Acetamide derivatives and their use as feeding behaviour modifiers
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The present invention relates to compounds of formula (I) wherein R1 is selected from H and 3-chloro; R2 is selected from a phenyl group and a pyridyl group; R3 and R4 are selected independently of each other from H and methyl; R5 and R6 are selected independently of each other from H and a pyridyl-methyl group or both represent an ethyl group; n=0 or 1; R1, R3, R4, R5 and R6 are not simultaneously H when R2 is phenyl. The salts of the compounds have a pyridyl group with pharmaceutical acceptable acids are also disclosed.
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- Solvolysis of benzylic chlorides with extended charge delocalization. α-tert-Butyl(2-naphthyl)methyl, 9-fluorenyl and monosubstituted benzhydryl chlorides
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Rate constants of solvolysis of α-tert-butyl(2-naphthyl)methyl chloride (1), 9-fluorenyl chloride (2) and a series of monosubstituted benzhydryl chlorides (3) in a wide range of solvents were measured. Grunwald-Winstein-type correlation analysis of log k for 2 and 3 against YBnCl, with or without nucleophilicity N, yielded less satisfactory linear correlations than that against log k(l). A new scale of solvent ionizing power, YxBnCl for the correlation of solvolytic reactivities of benzylic chlorides with extended charge delocalization based on log k(1) was developed. Application to the mechanistic study suggested the solvolysis of 2 and 4-nitrobenzhydryl chloride were non-limiting. Hammett plots against α+ constants exhibited more negative ρ values in less nucleophilic solvents. In a benzhydryl chloride containing a strong deactivating substituent, such as 4-nitro, the positive charge delocalizes mainly over the unsubstituted ring in the cationic transition state. The uneven charge distribution was also confirmed by Mulliken population analysis at the level of the RHF/6-31G*//RHF/3-21G(*) basis set for cations. Comparison of the results of correlation analysis using the equation log(k/k0) = mY vs the equation log(k/k0) = mY + hI, and using the equation log(k/k0) = mY +IN vs the equation log(k/ko) = mY + IN + hI indicated the use of YBnCl or YxBncl could give a better understanding of solvolytic mechanisms than the combinatorial use of YCl and I.
- Liu, Kwang-Ting,Lin, Yen-Shyi,Tsao, Meng-Lin
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p. 223 - 229
(2007/10/03)
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- Process for producing benzhydrols
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There is disclosed a process for producing benzhydrls by reacting an arylmetal compound with an aromatic aldehyde. According to this process, benzhydrols useful as raw materials for medicines and photopolymerization initiators can be produced in a high yield and industrially advantageously.
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- Reinvestigation of the Reaction of Sodium Borohydrate with Benzhydryl Halides under Solvolytic Conditions
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Solvolysis of benzhydryl halides in aqueous diglyme containing sodium borohydride was studied. Contrary to the literature, sodium borohydride was found not to be a convenient trap for benzhydryl carbocations, especially for those containing electron-withdrawing substituent, and it decomposed appreciably in 80% aqueous diglyme at 45 °C. In addition, significant acceleration of reactions due to the presence of sodium borohydride was realized in the solvolysis of 3-chloro- and 3-trifluoromethyl-benzhydryl chlorides.
- Liu, Kwang-Ting,Huang, Huei-Chin
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p. 249 - 252
(2007/10/03)
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- 3'-Chloro-3α-(diphenylmethoxy)tropane but not 4'-chloro-3α- (diphenylmethoxy)tropane produces a cocaine-like behavioral profile
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A series of 2'- and 3'-substituted and 3',3''-disubstituted 3α- (diphenylmethoxy)tropane analogs were designed and synthesized as novel probes for the dopamine transporter. All the analogs were evaluated for displacement of [3H]WIN 35,428 binding at the dopamine transporter and for inhibition of [3H]dopamine uptake in rat caudate putamen. Compounds were observed to monophasically displace [3H]WIN 35,428 binding to the dopamine transporter with affinities of 21.6-1836 nM (K(i)). Generally, meta- substituted compounds were more potent than benztropine and equipotent to or slightly less potent than their previously reported parasubstituted homologs in inhibiting [3H]WIN 35,428 binding. However, these same metasubstituted analogs were typically less potent than the 4'-substituted analogs in inhibiting [3H]dopamine uptake. Ortho-substituted analogs were generally less potent in both binding and inhibition of uptake at the dopamine transporter than either benztropine or other aryl-substituted homologs. The analogs were also tested for binding at norepinephrine and serotonin transporters as well as muscarinic m1 receptors. None of the compounds in the present study bound with high affinity to either the norepinephrine or serotonin transporters, but all bound to muscarinic m1 receptors with high affinity (K(i) = 0.41-2.52 nM). Interestingly, 3'-chloro-3α- (diphenylmethoxy)tropane (5c) produced effects like cocaine in animals trained to discriminate 10 mg/kg cocaine from saline, unlike its 4'-Cl homolog and all of the previously evaluated benztropine analogs. Further evaluation of compound 5c and the other benztropine analogs will undoubtedly prove useful in the elucidation of the role of the dopamine transporter in the reinforcing effects of cocaine and the ultimate identification of a cocaine-abuse treatment.
- Kline, Richard H.,Izenwasser, Sari,Katz, Jonathan L.,Joseph, David B.,Bowen, Wayne D.,Newman, Amy Hauck
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p. 851 - 857
(2007/10/03)
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- Benzylphosphonic acid inhibitors of human prostatic acid phosphatase
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A series of α-substituted benzylphosphonic acids is described as inhibitors of human prostatic acid phosphatase, an enzyme has been used as a model to study aryl phosphatases. The most potent inhibitors in this series are 2-trifluoromethylbenzhydrylphosphonic acid (9 μM), and α-(2-phenylethyl)benzylphosphonic acid (14 μM). The structure-activity studies suggest that bulk tolerance beyond the phosphate binding area limits the steric or hydrophobic contribution to inhibitor potency achieved through α-carbon substitution.
- Schwender,Beers,Malloy,Cinicola,Wustrow,Demarest,Jordan
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p. 311 - 314
(2007/10/03)
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- SOLVOLYSES OF MONOSUBSTITUTED BENZHYDRYL BROMIDES. NUCLEOPHILIC SOLVENT INTERVENTION AND DEPENDENCE OF SOLVATATION ON THE EXTENT OF CHARGE DELOCALIZATION IN CATIONIC TRANSITION STATES
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Solvolyses of monosubstituted benzhydryl bromides gave excellent linear correlations of logk with ?(1+) constants, and not with Y(BnBr) or Y(Br).Correlation analyses against corresponding logk of α-tert-butyl-(2-naphthyl)methyl bromide provided evidence for the importance of different extent of solvation in delocalized transition state and for nucleophilic solvent intervention in the solvolysis of benzhydryl systems.
- Liu, Kwang-Ting,Chin, Chien-Pu,Lin, Yen-Shyi,Tsao, Meng-Lin
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p. 6919 - 6922
(2007/10/02)
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- Behavior and extension of the scope of NADH models to the reduction of non-activated ketones by a stable indolo NADH model compound in the presence of Lewis acids
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The reduction of non-activated ketones, eg, acetophenone, by a very stable NADH model in the presence of Lewis acids (AlX3, Et2AlCl) is reported.During the reaction, a side equilibrated aldol condensation occurs.Due to the reversibility of this reaction, the overall yield in alcohol is not notably diminished.The scope of NADH models has been extended for the first time to non-activated ketones, such as dialkyl, aryl alkyl and diaryl ketones. - Keywords: NADH model / ketone reduction / Lewis acids / aldol condensation
- Berkous, Rabia,Dupas, Georges,Bourguignon, Jean,Queguiner, Guy
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p. 632 - 635
(2007/10/02)
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- A NEW PREPARATIVE METHOD FOR OPTICALLY ACTIVE DIARYLCARBINOLS
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Some diarylcarbinols were resolved efficiently by complexation with brucine.
- Toda, Fumio,Tanaka, Koichi,Koshiro, Kenzo
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p. 873 - 874
(2007/10/02)
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- ASSYMETRIC REDUCTIONS OF KETONES USING LITHIUM ALUMINIUM HYDRIDE MODIFIED WITH N,N-DIALKYL DERIVATIVES OF (R)-(-)-2-AMINOBUTAN-1-OL
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LiAlH4 previuosly treated with 2 equivalents of (R)-(-)-2-(2-iso-indolinyl)butan-1-ol (a readily available reagent) reduced 2-chloro and 2,4-dimethyl benzophenones into the corresponding benzhydrols with 100percent enantiomeric excess.Other examples of ketone reductions are given.
- Brown, Eric,Penfornis, Annie,Bayma, Joaquim,Touet, Joeul
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p. 339 - 342
(2007/10/02)
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- Studies on Enantioselective Addition of Chiral Titanium Reagents to Aromatic Aldehydes
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A series of substituted chiral benzhydrols were synthesized by reaction of aromatic aldehydes with the chiral intermediates formed from chiral titanates and arylmagnesium halides.The effect of substituents on the enantioselectivity of the reaction is studied.The reactions are carried out with two different chiral intermediates using two different procedures.
- Wang, Ji-Tao,Fan, Xiuju,Feng, Xiao,Qian, Yi-Min
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p. 291 - 292
(2007/10/02)
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- Mechanism of Base-Catalyzed Desilylations of Aryl- and Heteroaryltrimethylsilanes
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The influence of different bases on the cleavage of silicium-carbon bonds in aryl- and heteroaryltrimethylsilanes is investigated in the presence of benzaldehyde as electrophilic scavenger for the aryl and heteroaryl anions formed in this process.A reactivity gradation of the various basic catalysts employed is determined from the reactions with 2-(trimethylsilyl)benzothiazole (1).The increase of catalytic activity of the anions parallels that of their ion potential.Attack of the base at the Si atom is postulated as the first step in this reaction sequence, with subsequent dissociation of the pentacoordinated intermediate in the rate-determining step.The carbanion thus liberated rapidly reacts with benzaldehyde.In the differently substituted aryltrimethylsilanes 13, 13', and 13'' the dependency of aryl anion stability in the base-catalyzed carbodesilylation was investigated.The relative rates of reaction correlate with Hammett's ?-constants rather than with the corresponding aryl anion stabilities.
- Effenberger, Franz,Spiegler, Wolfgang
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p. 3872 - 3899
(2007/10/02)
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