Kinetics of Excited-State Ti(a5F)
... with a chemically attractive surface evolving from a Ti state having a 4s13d3configuration.15 For the reactions of Sc, Ti, and V with a given OX, this model predicts that rate constants should increase as k(Sc) < k(Ti) < k(V) since the energy differences of the 4s23d*2 (where n is the number of vale ...
... with a chemically attractive surface evolving from a Ti state having a 4s13d3configuration.15 For the reactions of Sc, Ti, and V with a given OX, this model predicts that rate constants should increase as k(Sc) < k(Ti) < k(V) since the energy differences of the 4s23d*2 (where n is the number of vale ...
18.10 CONJUGATE ADDITIONS
... The overall result of a conjugate addition is the addition of a proton and a nucleophile to the CC double bond. However, this reaction differs greatly from the additions discussed in Chapter 11, in which the electrophile adds first. Here, the nucleophile adds in the first step. This reaction does no ...
... The overall result of a conjugate addition is the addition of a proton and a nucleophile to the CC double bond. However, this reaction differs greatly from the additions discussed in Chapter 11, in which the electrophile adds first. Here, the nucleophile adds in the first step. This reaction does no ...
Ligand-Based CarbonАNitrogen Bond Forming Reactions of Metal
... cyclopentadienylcobalt dinitrosyl complex CpCo(NO)2 reacts reversibly with alkenes to give, in many cases, stable and isolable cobalt dinitrosoalkane complexes. More recently, we found that treatment with strong bases, such as lithium hexamethyldisilazide, Verkade's base, and phosphazene bases, depr ...
... cyclopentadienylcobalt dinitrosyl complex CpCo(NO)2 reacts reversibly with alkenes to give, in many cases, stable and isolable cobalt dinitrosoalkane complexes. More recently, we found that treatment with strong bases, such as lithium hexamethyldisilazide, Verkade's base, and phosphazene bases, depr ...
- Wiley Online Library
... hydrogen shift/halogenation for the preparation of a-fluoroketones.[9c,d] While this represented a success in terms of merging a transition-metal-catalyzed isomerization with an electrophilic halogenation, the formation of nonfluorinated ketones (5–20 %) could not be avoided and led to challenging s ...
... hydrogen shift/halogenation for the preparation of a-fluoroketones.[9c,d] While this represented a success in terms of merging a transition-metal-catalyzed isomerization with an electrophilic halogenation, the formation of nonfluorinated ketones (5–20 %) could not be avoided and led to challenging s ...
Addition of H 2 O to an Alkene
... Developing a Reaction Mechanism • Design experiments to reveal the details of a particular chemical reaction. • Propose a set or sets of steps that might account for the overall transformation. • A mechanism becomes established when it is shown to be consistent with every test that can ...
... Developing a Reaction Mechanism • Design experiments to reveal the details of a particular chemical reaction. • Propose a set or sets of steps that might account for the overall transformation. • A mechanism becomes established when it is shown to be consistent with every test that can ...
Iron(II) Chloride–1,1′-Binaphthyl-2,2′-diamine
... The reaction was completely suppressed by adding one equivalent of TEMPO (with respect to FeCl2), a radical trapping agent, to the reaction mixture. These results indicate that a radical intermediate is most likely involved in the initial steps of the domino transformation. This explains the observe ...
... The reaction was completely suppressed by adding one equivalent of TEMPO (with respect to FeCl2), a radical trapping agent, to the reaction mixture. These results indicate that a radical intermediate is most likely involved in the initial steps of the domino transformation. This explains the observe ...
Study Guide Chapter 16: The Process of Chemical Reactions
... are joined in a structure known as the activated complex, or transition state. 11. In a chemical reaction, the minimum energy necessary for reaching the activated complex and proceeding to products is called the activation energy. Only the collisions that provide a net kinetic energy equal to or gre ...
... are joined in a structure known as the activated complex, or transition state. 11. In a chemical reaction, the minimum energy necessary for reaching the activated complex and proceeding to products is called the activation energy. Only the collisions that provide a net kinetic energy equal to or gre ...
Name Reactions in Heterocyclic Chemistry-II
... section, pyrylium salts are easly converted by primary amines into pyridinium salts that are less reactive so that one can thus prepare conveniently pyridinium ionic liquids.51 Diisobutene affords on diacetylation with Ac2O and ZnCl2 a chlorozincate of 3 with R = CH2CMe3 (which can be converted into ...
... section, pyrylium salts are easly converted by primary amines into pyridinium salts that are less reactive so that one can thus prepare conveniently pyridinium ionic liquids.51 Diisobutene affords on diacetylation with Ac2O and ZnCl2 a chlorozincate of 3 with R = CH2CMe3 (which can be converted into ...
Lecture 3-edited
... Chromium is the 21st most abundant element in Earth's crust with atomic number 24. Naturally occurring chromium composed of three stable isotopes; 52Cr, 53Cr and 54Cr with 52Cr being most abundant. It has an electronic configuration of 3d5 4s1 and exhibits a wide range of oxidation states, where the ...
... Chromium is the 21st most abundant element in Earth's crust with atomic number 24. Naturally occurring chromium composed of three stable isotopes; 52Cr, 53Cr and 54Cr with 52Cr being most abundant. It has an electronic configuration of 3d5 4s1 and exhibits a wide range of oxidation states, where the ...
Amine-functionalized boehmite nanoparticle-supported
... BNPs), 1.00 g of BNPs was refluxed with MSPA (61 µL, 0.35 mmol) in dry toluene (50.0 mL) for 24 h (Scheme 1). The solid substance obtained was filtered off, washed three times with dry toluene, and dried at 100 °C overnight. The Mo(CO)6 and VOSO4·H2O complexes were used to sup ...
... BNPs), 1.00 g of BNPs was refluxed with MSPA (61 µL, 0.35 mmol) in dry toluene (50.0 mL) for 24 h (Scheme 1). The solid substance obtained was filtered off, washed three times with dry toluene, and dried at 100 °C overnight. The Mo(CO)6 and VOSO4·H2O complexes were used to sup ...
PPT File
... 10.3 Elimination Reactions of Alcohols Elimination of water, dehydration, is commonly obtained using sulfuric acid (H2SO4) as a catalyst. ...
... 10.3 Elimination Reactions of Alcohols Elimination of water, dehydration, is commonly obtained using sulfuric acid (H2SO4) as a catalyst. ...
biodiesel production via acid catalysis
... investigate the effect of the molar ratio of alcohol, the reaction temperature, the catalyst amount, the reaction time, and the presence of water and free fatty acids on the completeness of acid-catalyzed transesterification. Transesterification is the chemical process of converting one ester, in th ...
... investigate the effect of the molar ratio of alcohol, the reaction temperature, the catalyst amount, the reaction time, and the presence of water and free fatty acids on the completeness of acid-catalyzed transesterification. Transesterification is the chemical process of converting one ester, in th ...
Aldehydes and Ketones
... NAMING ALDEHYDES • ALDEHYDES ARE NAMED BY REPLACING THE FINAL “E” OF THE NAME OF THE ALKANE WITH THE SAME NUMBER OF CARBONS TO “AL”. • BECAUSE IN ALDEHYDES THE CARBONYL GROUP IS ALWAYS ATTACHED TO THE FIRST CARBON, THERE IS NO NEED TO PLACE A 1 IN FRONT OF THE NAME. • IF THERE ARE SUBSTITUENTS PRES ...
... NAMING ALDEHYDES • ALDEHYDES ARE NAMED BY REPLACING THE FINAL “E” OF THE NAME OF THE ALKANE WITH THE SAME NUMBER OF CARBONS TO “AL”. • BECAUSE IN ALDEHYDES THE CARBONYL GROUP IS ALWAYS ATTACHED TO THE FIRST CARBON, THERE IS NO NEED TO PLACE A 1 IN FRONT OF THE NAME. • IF THERE ARE SUBSTITUENTS PRES ...
Fluorinated Alcohols Enable Olefin Epoxidation by H2O2
... 6-311G**, which was abandoned in favor of the more extended basis set. The reaction critical points for the epoxidation pathways in Scheme 1 were studied by gradient optimization. All the TSs were verified by frequency calculations. The reaction mechanisms for the smaller systems, (e,n) and (e,F3) w ...
... 6-311G**, which was abandoned in favor of the more extended basis set. The reaction critical points for the epoxidation pathways in Scheme 1 were studied by gradient optimization. All the TSs were verified by frequency calculations. The reaction mechanisms for the smaller systems, (e,n) and (e,F3) w ...
Changing counterion can switch the preference for selective 1,2
... Another example of a selectivity-controlled reaction of alkenes is hydroformylation via the use of scaffolding ligands. These bind covalently and reversibly to the substrate, leading to a temporarily intramolecular transformation that can lead to dramatically improved and reversed selectivity with s ...
... Another example of a selectivity-controlled reaction of alkenes is hydroformylation via the use of scaffolding ligands. These bind covalently and reversibly to the substrate, leading to a temporarily intramolecular transformation that can lead to dramatically improved and reversed selectivity with s ...
Copper perchlorate: Efficient acetylation catalyst
... achieved in contrast to some other catalysts. Acylal formation from aldehydes is found to be very rapid and at the same time keto groups remain unchanged. Thus the transition metal perclorates are better for acetylation hederoatoms and aldehydes than other metal perclorates and metal triflates. It m ...
... achieved in contrast to some other catalysts. Acylal formation from aldehydes is found to be very rapid and at the same time keto groups remain unchanged. Thus the transition metal perclorates are better for acetylation hederoatoms and aldehydes than other metal perclorates and metal triflates. It m ...
Aldehydes, Ketones and Carboxylic acids
... Sterically, the presence of two bulky (large) groups in ketones will hinder the attack of nucleophile to carbonyl carbon in ketone. Aldehydes have only one bulky group around the carbonyl carbon and it is easier for the nucleophile to attack the carbonyl carbon as compared to ketones. Electronically ...
... Sterically, the presence of two bulky (large) groups in ketones will hinder the attack of nucleophile to carbonyl carbon in ketone. Aldehydes have only one bulky group around the carbonyl carbon and it is easier for the nucleophile to attack the carbonyl carbon as compared to ketones. Electronically ...
FULL PAPER Observations on the Influence of Precursor
... rationalizing the success or failure of macrocyclizations of large rings.12 The success of using simple force-field based modeling on the conformations of small and medium-sized rings was achieved already in the early and mid-1980s by Still and coworkers13 and molecular mechanics calculations have b ...
... rationalizing the success or failure of macrocyclizations of large rings.12 The success of using simple force-field based modeling on the conformations of small and medium-sized rings was achieved already in the early and mid-1980s by Still and coworkers13 and molecular mechanics calculations have b ...
ALKENES INTRODUCING
... High density poly(ethene) has very little branching along the hydrocarbon chains - the crystallinity is 95% or better. This better packing means that van der Waals attractions between the chains are greater and so the plastic is stronger and has a higher melting point. Its density is also higher bec ...
... High density poly(ethene) has very little branching along the hydrocarbon chains - the crystallinity is 95% or better. This better packing means that van der Waals attractions between the chains are greater and so the plastic is stronger and has a higher melting point. Its density is also higher bec ...
Tr-dT, 2-cyanoethanol
... Tr-dT was dissolved 1-2 hours before use in pyridine containing small amounts ( 0.2 mole equivalent) of TPS to remove the traces of water usually present in the Tr-dT powder. The solutions of Tr-dT and B type derivative were mixed in dry box and the disappearance of the B signal was followed. The in ...
... Tr-dT was dissolved 1-2 hours before use in pyridine containing small amounts ( 0.2 mole equivalent) of TPS to remove the traces of water usually present in the Tr-dT powder. The solutions of Tr-dT and B type derivative were mixed in dry box and the disappearance of the B signal was followed. The in ...
Lecture 31 Homogeneous catalysis
... The homogeneous catalyst precursors are added in the reaction system in different forms and are transformed into the active form insitu. During one catalytic cycle, the catalyst may pass through several intermediate forms and finally produce the products. After end of each catalytic cycle, the catal ...
... The homogeneous catalyst precursors are added in the reaction system in different forms and are transformed into the active form insitu. During one catalytic cycle, the catalyst may pass through several intermediate forms and finally produce the products. After end of each catalytic cycle, the catal ...
INTRODUCING ALDEHYDES AND KETONES
... This page gives you the facts and simple, uncluttered mechanisms for the nucleophilic addition reactions between carbonyl compounds (specifically aldehydes and ketones) and hydrogen cyanide, HCN. If you want the mechanisms explained to you in detail, there is a link at the bottom of the page. Aldehy ...
... This page gives you the facts and simple, uncluttered mechanisms for the nucleophilic addition reactions between carbonyl compounds (specifically aldehydes and ketones) and hydrogen cyanide, HCN. If you want the mechanisms explained to you in detail, there is a link at the bottom of the page. Aldehy ...
Amino Alcohol Oxidation with Gold Catalysts: The Effect of Amino
... catalysts, represents a suitable alternative. The main problem lies on the high affinity of nitrogen for metal such as Pt or Pd, which lead to active sites blocking [7]. Gold catalyst appeared more resistant, and therefore applicable [8]. It has been shown, for example, that alaninol can be directly ...
... catalysts, represents a suitable alternative. The main problem lies on the high affinity of nitrogen for metal such as Pt or Pd, which lead to active sites blocking [7]. Gold catalyst appeared more resistant, and therefore applicable [8]. It has been shown, for example, that alaninol can be directly ...
Imbalanced tunneling ready states in alcohol dehydrogenase
... been challenging.9,10 Since the early 1980’s, 21 deuterium or tritium (H/D or H/T) KIEs for many H-transfer reactions, both in solution and in enzymes, have been observed to be larger than the value predicted by the classical TS, and even outside of the range between unity and 21 EIEs.9–16 This has ...
... been challenging.9,10 Since the early 1980’s, 21 deuterium or tritium (H/D or H/T) KIEs for many H-transfer reactions, both in solution and in enzymes, have been observed to be larger than the value predicted by the classical TS, and even outside of the range between unity and 21 EIEs.9–16 This has ...
Ene reaction
The ene reaction (also known as the Alder-ene reaction) is a chemical reaction between an alkene with an allylic hydrogen (the ene) and a compound containing a multiple bond (the enophile), in order to form a new σ-bond with migration of the ene double bond and 1,5 hydrogen shift. The product is a substituted alkene with the double bond shifted to the allylic position.This transformation is a group transfer pericyclic reaction, and therefore, usually requires highly activated substrates and/or high temperatures. Nonetheless, the reaction is compatible with a wide variety of functional groups that can be appended to the ene and enophile moieties. Also,many useful Lewis acid-catalyzed ene reactions have been developed which can afford high yields and selectivities at significantly lower temperatures, making the ene reaction a useful C–C forming tool for the synthesis of complex molecules and natural products.