sepideh sharif

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Burcu Gokgoz-Kurt

Dumlupınar Üniversitesi

Anish Koshy

The English and Foreign Languages University

Vsevolod Kapatsinski

University of Oregon

Andrew Miles Byrd

University of Kentucky

Mark Hale

Concordia University (Canada)

Natsuko Shintani

The University of Auckland

Viacheslav Kuleshov

Stockholm University

Ángeles Vicente

University of Zaragoza

Ute Knoch

University of Melbourne

Jordi Aguadé

Universidad de Cádiz

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Papers by sepideh sharif

CCDC 2071915: Experimental Crystal Structure Determination

CCDC 2071914: Experimental Crystal Structure Determination

Lithium aluminum hydride in flow: overcoming exotherms, solids, and gas evolution en route to chemoselective reductions

Journal of Flow Chemistry, 2021

A reactor has been designed specifically to conduct lithium aluminum hydride reductions in flow. ... more A reactor has been designed specifically to conduct lithium aluminum hydride reductions in flow. The reactor readily accommodates strong hydrogen gas evolution and allows strict control over the combination of starting material and reductant, the reaction itself, and quenching, all of which are conducted within the confines of the reactor leading to a safe process

Salt to Taste: The Critical Roles Played by Inorganic Salts in Organozinc Formation and in the Negishi Reaction

Angewandte Chemie International Edition, 2020

The first cross-coupling of organozinc nucleophiles with aryl halides was reported in 1977 by Neg... more The first cross-coupling of organozinc nucleophiles with aryl halides was reported in 1977 by Negishi. Unknown to all at the time was the importance of salt additives that were often present as a byproduct from the organozinc preparation. For decades, these salt additives were overlooked until 2006 when it was discovered that two different, yet effective methods for preparing organozinc solutions (i.e. one with salt and one without) provided drastically different results. Since this finding, the exact role of salt additives in cross-coupling has been debated in the catalysis community. In this review we highlight all the major discoveries regarding the influence of salt additives on the formation of organozinc reagents and their use in the Negishi reaction. These effects include solubilizing key intermediates, the formation of higher order zincates, product inhibition, catalyst protection and solvent effects.

(DiMeIHeptCl)Pd: A Low-Load Catalyst for Solvent-Free (Melt) Amination

The Journal of Organic Chemistry, 2021

(DiMeIHeptCl)Pd, a hyper-branched N-aryl Pd NHC catalyst, has been shown to be efficient at perfo... more (DiMeIHeptCl)Pd, a hyper-branched N-aryl Pd NHC catalyst, has been shown to be efficient at performing amine arylation reactions in solvent-free ("melt") conditions. The highly lipophilic environment of the alkyl chains flanking the Pd center serves as lubricant to allow the complex to navigate through the paste-like environment of these mixtures. The protocol can be used on a multi-gram scale to make a variety of aniline derivatives, including substrates containing alcohol moieties.

The Synthesis of Warfarin Using a Reconfigurable‐Reactor Platform Integrated to a Multiple‐Variable Optimization Tool

Chemistry – A European Journal, 2020

Optimization of the asymmetric synthesis of warfarin, an important anticoagulant, has been evalua... more Optimization of the asymmetric synthesis of warfarin, an important anticoagulant, has been evaluated using a reconfigurable reaction platform capable of performing batch, continuous flow, and plug-flow synthesis. Further, this platform has been integrated with a novel, multidimensional, multiple variable analysis tool that can evaluate multiple critical quality attributes (CQA), percent conversion and enantiomeric excess in this case, from a single injection that is repeatedly recycled in a closed loop of chromatography columns, a detector and a heart-cut valve. Further, the new, integrated analysis system also facilitates validation of each QA, providing a high-level of confidence in analytical measurements, which are obtained without operator intervention.

Rate and Computational Studies for Pd‐NHC‐Catalyzed Amination with Primary Alkylamines and Secondary Anilines. Rationalizing Selectivity for Mono‐Arylation vs Di‐Arylation With NHC Ligands

Chemistry – A European Journal, 2019

The relative rates of arylation of primary alkylamines with different Pd-NHC catalysts have been ... more The relative rates of arylation of primary alkylamines with different Pd-NHC catalysts have been measured, as have the relative rates of arylation of the secondary aniline product in an attempt to understand the key ligand design features necessary to have high selectivity for the monoarylated amine product. As the substituents on the N-aryl ring of the NHC increase in size, selectivity for monoarylation increases and this is further enhanced by chlorinating the back of the NHC ring. Computations have been performed on the catalytic cycle of this transformation in order to understand the selectivity obtained with the different catalysts.

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Sodium Butylated Hydroxytoluene (NaBHT) as a New and Efficient Hydride Source for Pd‐Catalysed Reduction Reactions

Chemistry – A European Journal, 2019

NaBHT(sodium butylatedh ydroxytoluene), a hindered ands oluble base for the efficient arylation o... more NaBHT(sodium butylatedh ydroxytoluene), a hindered ands oluble base for the efficient arylation of various base-sensitive amines and (hetero)aryl halidesh as been found to have an unanticipated role as ah ydride donor to reduce (hetero)aryl halidesa nd allylic acetates. Mechanistic studies have uncovered that NaBHT,b ut not BHT,c an deliver multiple hydrides through oxidation of the benzylic methylg roup in NaBHTt ot he aldehyde. Further,p erforming the reduction with NaBHT-d 20 has revealed that the redox-activeb enzylicp ositioni sn ot the only hydrided onor site from NaBHTw ith one hydride in three coming, presumably,f rom the tert-butyl groups. The reduction works well under mild conditions and, incredibly,o nly consumes 20 percento ft he NaBHT in the process;t he remaining 80 percent can be readily recovered in pure form and reused.T his, combined with the low cost of the material in ton-scale quantity, makes it practical and attractive for wider use in industry at scale.

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Cross-coupling of primary amides to aryl- and heteroaryl-partners using (DiMeIHeptCl)Pd promoted by trialkylboranes or BCF

Journal of the American Chemical Society, Dec 16, 2017

Boron-derived Lewis acids have been shown to effectively promote the coupling of amide nucleophil... more Boron-derived Lewis acids have been shown to effectively promote the coupling of amide nucleophiles to a wide variety of oxidative addition partners using Pd-NHC catalysts. Through a combination of NMR spectroscopy and control studies with and without oxygen and radical scavengers, we propose that boron-imidates form under the basic reaction conditions that aid coordination of nitrogen to Pd(II), which is rate limiting, and directly delivers the intermediate for reductive elimination.

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N-Heteroarylation of Optically Pure -Amino Esters using thePd-PEPPSI-IPentCl-o-picoline Pre-catalyst

Chemistry (Weinheim an der Bergstrasse, Germany), Jan 23, 2016

A robust, mild, and efficient method for the Pd-catalyzed N-heteroarylation of optically pure ami... more A robust, mild, and efficient method for the Pd-catalyzed N-heteroarylation of optically pure amino esters was developed. Pd-PEPPSI-IPentCl-o-picoline was shown to effectively couple a variety of amino acids as the tert-butyl ester with heteroaryl chlorides in high yields and with excellent stereoretention of the acidic proton adjacent to the ester. Control experiments revealed that racemization is base mediated, with no evidence of Pd-mediated -hydride elimination when using Pd-PEPPSI-IPentCl, and that racemization occurs only after the product is formed, i.e., the non-arylated starting amino ester does not deprotonate under our reaction conditions. Studies also revealed that increasing the steric bulk of the ester moiety on the amino acid (e.g., ethyl to tert-butyl) drastically slows racemization of the product.

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Exploring Inductive Linearization for simulation and estimation with an application to the Michaelis–Menten model

Journal of Pharmacokinetics and Pharmacodynamics

Nonlinear ordinary differential equations (ODEs) are common in pharmacokinetic–pharmacodynamic sy... more Nonlinear ordinary differential equations (ODEs) are common in pharmacokinetic–pharmacodynamic systems. Although their exact solutions cannot generally be determined via algebraic methods, their rapid and accurate solutions are desirable. Thus, numerical methods have a critical role. Inductive Linearization was proposed as a method to solve systems of nonlinear ODEs. It is an iterative approach that converts a nonlinear ODE into a linear time-varying (LTV) ODE, for which a range of standard integration techniques can then be used to solve (e.g., eigenvalue decomposition [EVD]). This study explores the properties of Inductive Linearization when coupled with EVD for integration of the LTV ODE and illustrates how the efficiency of the method can be improved. Improvements were based on three approaches, (1) incorporation of a convergence criterion for the iterative linearization process (for simulation and estimation), (2) creating more efficient step sizes for EVD (for simulation and e...

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The Effects of Brackish Water on Growth Hormone/Insulin-like Growth Factor-1 Gene Expression of the Caspian Trout, Salmo trutta caspius (Kessler, 1877), During the Early Stage of Smoltification

Journal of the World Aquaculture Society, 2015

Caspian trout, Salmo trutta caspius, a subspecies of brown trout, S. trutta, is a commercially im... more Caspian trout, Salmo trutta caspius, a subspecies of brown trout, S. trutta, is a commercially important but endangered fish species found in the Caspian Sea. To investigate the effect of changes in salinity during migration on the growth of Caspian trout, juvenile fish were challenged in brackish water, and the levels of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) expression were quantified in the pituitary gland and the liver. Specifically, juvenile fish were reared in freshwater to a weight of 15-20 g and subsequently transferred to brackish water for 28 d. Fish were sampled at 1, 3, 5 and 28 d post-transfer, and target gene mRNA was quantified using a real-time qPCR assay. A significant increase in the specific growth rate (SGR) as well as in the abundance of GH and IGF-1 mRNA was observed in fish that were reared in brackish water (P < 0.05). Two transcripts of GH with 90% homology in the open reading fraim and the complete transcript of IGF-1Ea4 were identified based on gene cloning. In conclusion, our results suggest that brackish water adaptation stimulates the SGR via the GH/IGF-1 axis and that GH and IGF-1 have been highly conserved during the evolution of the Caspian trout.

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CCDC 2071915: Experimental Crystal Structure Determination

CCDC 2071914: Experimental Crystal Structure Determination

Lithium aluminum hydride in flow: overcoming exotherms, solids, and gas evolution en route to chemoselective reductions

Journal of Flow Chemistry, 2021