The Cu-catalyzed hydroboration of alkynes in operationally simple and environmentally friendly conditions is reported.

a b s t r a c tA novel series of tacrine-lophine hybrids was synthesized and tested for their ability to inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) with IC 50 in the nanomolar concentration scale. The key step is the one-pot four component condensation reaction of 9-aminoalkylamino-1,2,3,4-tetrahydroacridines, benzil, different substituted aromatic aldehydes and NH 4 OAc, using InCl 3 as the best catalyst. Tacrine-lophine hybrids were found to be potent and selective inhibitors of cholinesterases. As an extension of the four component approach to tetrasubstituted imidazoles, a new series of bis-(2,4,5-triphenyl-1H-imidazoles) or bis(n)-lophines was tested against AChE and BuChE.

Nesse trabalho estudou-se a reação de ciclodesidratação entre antranilonitrila e várias cetonas na presença de diferentes ácidos de Lewis não reportados na literatura, para a obtenção de 9-amino-1,2,3,4-tetrahidroacridinas. As reações de ciclodesidratação foram realizadas em condições térmicas empregando-se diferentes solventes e também na ausência de solvente, seguidas de hidrólise alcalina, levando à obtenção dos produtos em bons a excelentes rendimentos após isolamento.The scope of Lewis acid-promoted cyclodehydratation reactions between anthranilonitrile and several ketones, to afford tacrine and its derivatives, was expanded to include the use of various metal chloride salts not reported in the literature. The ability of the Lewis acids to effectively promote the cyclodehydratation between anthranilonitrile and cyclohexanone as the ketone was found to be the following order: InCl 3 > AlCl 3 ~ BF 3 .Et 2 O > FeCl 3 > BiCl 3 ~ SbCl 3 ~ SnCl 2 .2H 2 O. The reactions were performed under both solvent and solvent-free conditions in good to excellent yields. Other Lewis acids screened, such as RuCl 3 , CeCl 3 , NiCl 2 , CoCl 2 .2H 2 O and CsCl were not effective.

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Tricloreto de índio na presença de hipoclorito de sódio promove a cloração alílica de olefinas terminais em meio bifásico (diclorometano/água) com bons rendimentos. Para estabelecer um procedimento geral, escolheu-se a carvona como composto modelo e otimizou-se a estequiometria, temperatura, e tempo de conversão para o respectivo cloreto alílico. Tratando-se β-pineno com tricloreto de índio/hipoclorito de sódio obteve-se seletivamente o cloreto perílico, um precursor importante para a obtenção de derivados de limoneno oxigenados no carbono C-7.Indium trichloride promotes the chlorination of terminal olefins in the presence of sodium hypochlorite with good results. Carvone was chosen as a model compound to examine some of the general features of this reaction, such as stoichiometry, temperature, reaction time and product conversion. Treatment of β-pinene with sodium hypochlorite in the presence of indium trichloride resulted in a facile rearrangement to selectively yield perillyl chloride, which is an important precursor for C-7 oxygenated limonenes.

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Cholinesterase enzymes are important targets for the therapy of Alzheimer's disease. Tacrine-based dual binding site cholinesterases inhibitors are potential disease-modifying anti-Alzheimer drug candidates. In the present work, we described the synthesis of a series of chiral homo-and heterodimers of bis (7)-tacrine connected by a heptylene chain as a spacer with the methyl substituent at the C-3 position of the alicyclic region of tacrine nucleus and/or a chlorine atom attached to the C-6. Friedländer cyclocondensation between (R) or (S) 3-methylcyclohexanone prepared from monoterpene pulegone and o-aminobenzoic acids in the presence of POCl 3 afford 9-chloroacridines as intermediates, which were used to the synthesis of homo-and heterodimers. All compounds demonstrated to be potent inhibitors of acetylcholinesterase (AChE) at low nanomolar concentration and showed selectivity for AChE over butyrylcholinesterase (BuChE). Furthermore, the affinity difference between enantiomeric bis(7)-tacrine analogues series indicated some degree of stereoselectivity in the active site of AChE for chiral bis-cognitin compounds. Keywords: bistacrine, chiral, cholinesterases, synthesis, molecular docking IntroductionAlzheimer's disease (AD) is one of the leading causes of death among elderly people in the World, and its treatment remains a challenge for the pharmaceutical community. Nearly a million new cases per year it is expected to emerge by 2050.1,2 The proposed cholinergic hypothesis of cognitive impairment has been accepted for decades to explain AD and is characterized by the loss of cholinergic basal forebrain, and their projections to the cerebral cortices. 2,3 According to this hypothesis, the memory and cognitive decline well-marked in AD result from a deficit of the important neurotransmitter acetylcholine (ACh). In this context, the inhibition of cholinesterase enzymes (ChEs) that are responsible for the hydrolyses of ACh emerge as a symptomatic treatment to relieve these symptoms. [4][5][6] The current therapeutic options for AD are limited to three inhibitors of acetylcholinesterase (AChEI):4-8 donepezil (Aricept ® ), rivastigmine (Exelon ® ) and galantamine (Razadyne ® , Reminyl ® ). In addition, the N-methyl-D-aspartate (NMDA) receptor antagonist memantine (Namenda ® ) is also used. [9][10][11] However, none of these therapeutic options represent a real cure.The cholinesterase enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) are enzymes which are found in the central nervous system (CNS) and catalyze the hydrolysis of ACh efficiently but at different rates. [9][10][11][12] However, as AD progresses, the activity of AChE decreases, while that of BuChE significantly increases and may even surpass the AChE activity. 13,14 The acetylcholine binding site of AChE is located at the base of a deep hydrophobic channel measuring Lopes et al. 2219 Vol. 28, No. 11, 2017 approximately 20 Å in length. It is formed by a catalytic anionic site (CAS) composed by the catalytic triad Ser200, His440 and Gl...

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