Topic
Reagent
About: Reagent is a research topic. Over the lifetime, 60091 publications have been published within this topic receiving 1234928 citations. The topic is also known as: reagens.
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TL;DR: The selective formation of partially protected nonsymmetric 2,2'-biphenols via electroorganic synthesis was accomplished with a high yield of isolated product and facilitates a large variety of new substrate combinations for oxidative cross-coupling reactions.
Abstract: The oxidative cross-coupling of aromatic substrates without the necessity of leaving groups or catalysts is described. The selective formation of partially protected nonsymmetric 2,2'-biphenols via electroorganic synthesis was accomplished with a high yield of isolated product. Since electric current is employed as the terminal oxidant, the reaction is reagent-free; no reagent waste is generated as only electrons are involved. The reaction is conducted in an undivided cell, and is suitable for scale-up and inherently safe. The implementation of O-silyl-protected phenols in this transformation results in both significantly enhanced yields and higher selectivity for the desired nonsymmetric 2,2'-biphenols. The use of a bulky silyl group to block one hydroxyl moiety makes the final product less prone to oxidation. Furthermore, the partially silyl-protected 2,2'-biphenols are versatile building blocks that usually require tedious or low-yielding synthetic pathways. Additionally, this strategy facilitates a large variety of new substrate combinations for oxidative cross-coupling reactions.
144 citations
TL;DR: In this article, a chiral helical titanium reagent from titanium tetraiopropoxide and chiral ligand derived from optically pure binaphthol was used as an efficient chiral template for the sufficient conformational fixation of α,β-unsaturated aldehydes.
Abstract: A new type of chiral helical titanium reagent has been prepared from titanium tetraiopropoxide and a chiral ligand derived from optically pure binaphthol. These reagents have been successfully utilized as an efficient chiral template for the sufficient conformational fixation of α,β-unsaturated aldehydes, thereby allowing efficient enantioface recognition of the substrates for achievement of uniformly high symmetric induction in asymmetric Diels-Alder reaction with dienes, regardless of reaction temperature
143 citations
Patent•
27 May 1992TL;DR: The use of such mixtures allows for the delay of reagent mixing until the first heating step of a PCR amplification, thereby reducing the enzymatic generation of nonspecific products which occurs when a complete mixture of PCR reagents, with or without test sample, stands at room temperature or below as discussed by the authors.
Abstract: Improvements to the polymerase chain reaction (PCR), a process for in vitro enzymatic amplification of specific nucleic acid sequences, can be achieved by changing the way that PCR reagents are mixed and the enzymatic reaction is started and by the replacement of mineral oil, commonly used as a vapor barrier to minimize solvent evaporation, by a grease or wax. The use of such mixtures allows for the delay of reagent mixing until the first heating step of a PCR amplification, thereby reducing the enzymatic generation of nonspecific products which occurs when a complete mixture of PCR reagents, with or without test sample, stands at room temperature or below. These mixtures increase the shelf-life of PCR reagents and increase protection of the laboratory environment against contamination by PCR product.
143 citations
TL;DR: The super electrophilicity of a shelf-stable, easily prepared trifluoromethylthio-dibenzenesulfonimide 7 was demonstrated and exhibits reactivity remarkably higher than that of other known electrophilic trifLUorometHylthiolating reagents.
Abstract: The super electrophilicity of a shelf-stable, easily prepared trifluoromethylthiolating reagent N-trifluoromethylthio-dibenzenesulfonimide 7 was demonstrated. Consistent with the theoretical prediction, 7 exhibits reactivity remarkably higher than that of other known electrophilic trifluoromethylthiolating reagents. In the absence of any additive, 7 reacted with a wide range of electron-rich arenes and activated heteroarenes under mild conditions. Likewise, reactions of 7 with styrene derivatives can be fine-tuned by simply changing the reaction solvents to generate trifluoromethylthiolated styrenes or oxo-trifluoromethylthio or amino-trifluoromethylthio difunctionalized compounds in high yields.
143 citations
TL;DR: In this article, a simple approach for the aqueous room temperature synthesis of marigold shape single crystalline fluorescent gold nanoflowers without using seeds or structure-regulating reagent and their SERS and electrocatalytic activity is described.
Abstract: A simple approach for the aqueous room temperature synthesis of marigold shape single crystalline fluorescent gold nanoflowers without using seeds or structure-regulating reagent and their SERS and electrocatalytic activity is described.
143 citations