I think mastering Kokomi/Raiden involves strong understanding Electro-charged reactions... so I'm doing a mini quiz for the fellow Kokomi mains out there to help us learn how to use her better.
Wet, Overload, Electro-charged, Vaporize, Swirl - 5 in an instance
In the picture above there are 5 status effects/elemental reactions in one rotation - Swirl, Electro-charged, Wet, Vaporize, Overloaded.
Any guesses to how this was possible or what happened during the rotation order to proc 5 elemental reactions/statuses in an instant?
Tip: has nothing to do with weapons/artifacts they are using, everything you need is on screen
EDIT: Answers in comments below
Journal of the American Chemical SocietyDOI: 10.1021/jacs.1c04976
Suryansh Singh, Hanna Lyle, Luca D’Amario, Elena Magnano, Ilya Vinogradov, and Tanja Cuk
https://ift.tt/2WaPDRa
Lets assume have a methane and chlorine gas, and we add heat so they would react.
I understand that, once the reaction takes place and some time has passed, the concentration of the free radicals intermediates increases, and we have more varied products, like dichloromethane and even ethane.
Could we keep reacting in order to have longer alkanes as products (eg. two ethanes free radicals reacting, or a methane free radical reacting with an ethane free radical)? Or even multi chloro alkanes (eg. an ethane free radical reacting with a di-chloromethane free radical)?
How the concentration of each compound (or time passed since the initial step) would influenciate on that?
Thinking about it a little further, i know that the more subtituents it has, the more stable the free radical, so i assume we would have way more shorter and ramificated alkanes or halo-alkanes than longer ones, right? (i mean, its way more probable that, reacting methane and chlorine long enough, we would get 2,3-dimethylbutane than an hexane, or even methylpentane. we could even get halil alkanes derivatives, like 2,3-dimethyl-2-chlorobutane.)
EDIT: would we be able to make one of the methyls the leaving group, so we get 2-chloro-3-methylbutane from methane chlorination?
I just wanna know if my head is in the right place.
BTW, sorry for my english, its not my first language.
Journal of the American Chemical SocietyDOI: 10.1021/jacs.1c04652
Nicholas A. Till, Seokjoon Oh, David W. C. MacMillan, and Matthew J. Bird
https://ift.tt/3gs7lHh
Metal-catalyzed acylnitrene transfer reactions are widely proposed to proceed via M(NCOR) intermediates. In their Research Article (DOI: 10.1002/anie.202100668), Chi-Ming Che and co-workers report [Ru(Por)Cl2]-catalyzed highly selective acylnitrene transfer to alkenes, indoles, silyl enol ethers, and C(sp3)−H bonds to afford aziridines/oxazolines, 3-aminoindoles, α-aminoketones, and N-acyl amines, respectively, and also experimental and computational evidence that porphyrin-supported Ru(NCOR) intermediates, which belong to RuV-imido species, are involved in these reactions.
https://ift.tt/2TRgsZc
Experimental studies including ESI-MS, EPR spectroscopy and KIE, and also DFT calculations point to the intermediacy of a porphyrin-supported RuV(NCOR) species in [RuIV(Por)Cl2]-catalyzed C−N bond formation reactions with acyl azides N3COR (up to 99 % yield). The [RuIV(Por)Cl2]/N3COR catalytic method is applicable to various substrates, including alkenes, indoles, silyl enol ethers, and C(sp3)−H bonds.
Abstract
Metal-catalyzed C−N bond formation reactions via acylnitrene transfer have recently attracted much attention, but direct detection of the proposed acylnitrenoid/acylimido M(NCOR) (R=aryl or alkyl) species in these reactions poses a formidable challenge. Herein, we report on Ru(NCOR) intermediates in C−N bond formation catalyzed by [RuIV(Por)Cl2]/N3COR, a catalytic method applicable to aziridine/oxazoline formation from alkenes, amination of substituted indoles, α-amino ketone formation from silyl enol ethers, amination of C(sp3)−H bonds, and functionalization of natural products and carbohydrate derivatives (up to 99 % yield). Experimental studies, including HR-ESI-MS and EPR measurements, coupled with DFT calculations, lend evidence for the formulation of the Ru(NCOR) acylnitrenoids as a RuV-imido species.
https://ift.tt/3geiGdY
The first carbene-catalyzed highly enantioselective addition involving cumulenolates is disclosed. Both allene and spirooxindole products could be accessed with high yields and excellent enantioselectivities by varying the amount of the base.
Abstract
Azolium cumulenolates are a special type of intermediates in N-heterocyclic carbene catalysis. They contain elongated linear structures with three contiguous C=C bonds and sterically unhindered α-carbon atoms. These structural features make it difficult to develop enantioselective reactions for these intermediates. Here we disclose the first carbene-catalyzed highly enantioselective addition reactions of azolium cumulenolates. The reaction starts with alkynals as the precursors for azolium cumulenolate intermediates that undergo enantioselective addition to activated ketones. From the same set of substrates, both allene and spirooxindole products can be obtained with high yields and excellent enantioselectivities. The allene moieties in our optically enriched products carry rich reactivities and can be transformed to diverse molecules. The spirooxindole scaffolds in our products are important structural motifs in natural products and medicines.
https://ift.tt/3mvo4L8
Palladium(II) boronates are recognized as fundamental pre‐transmetalation intermediates in Suzuki–Miyaura cross‐couplings. While these typically transient species have been detected and studied spectroscopically, it is conspicuous that they have never been isolated since this important reaction was discovered over forty years ago. This study reports the synthesis of a family of unprecedented arylpalladium(II) boronates that are, by design, kinetically stable at ambient temperature, both in solution and in the solid state. These properties enabled unambiguous crystallographic confirmation of their structure for the first time and their chemical competence in a Suzuki–Miyaura reaction was demonstrated.
https://ift.tt/2QPiBmG
Edit: the temperature is around 200 Kelvin for the LDA reaction
A. Alkyl halide to alcohol
B. Alkyl halide to an alkene
C. Alkene to alkyl halide
D. Alcohol to alkyl halide
E. Alcohol to alkene
F. Alkene to alcohol
I don't know why but I can't figure out what happens to the epoxide. Is isosafrole glycol formed? I have a suspicion the answer is right in front of my face but I have no idea.
In the buffered reaction there's no isosaf. monoformyl glycol right?
HOR on Au@PtNi surfaces in alkaline media has been investigated by in situ surface‐enhanced Raman spectroscopy (see picture). Direct spectroscopic evidence for OHad species was observed and further confirmed by deuterium isotopic experiments and DFT.
Abstract
Elucidating hydrogen oxidation reaction (HOR) mechanisms in alkaline conditions is vital for understanding and improving the efficiency of anion‐exchange‐membrane fuel cells. However, uncertainty remains around the alkaline HOR mechanism owing to a lack of direct in situ evidence of intermediates. In this study, in situ electrochemical surface‐enhanced Raman spectroscopy (SERS) and DFT were used to study HOR processes on PtNi alloy and Pt surfaces, respectively. Spectroscopic evidence indicates that adsorbed hydroxy species (OHad) were directly involved in HOR processes in alkaline conditions on the PtNi alloy surface. However, OHad species were not observed on the Pt surface during the HOR. We show that Ni doping promoted hydroxy adsorption on the platinum‐alloy catalytic surface, improving the HOR activity. DFT calculations also suggest that the free energy was decreased by hydroxy adsorption. Consequently, tuning OH adsorption by designing bifunctional catalysts is an efficient method for promoting HOR activity.
https://ift.tt/3gTpOuJ
Based on the diagram I have drawn below, I would expect that the rate determining step would be the first transition state, and that sterics would still govern the rate of reaction (with methyl being fastest as in an sn2 reaction) since greater substitution would mean a more crowded and unstable transition state. I know that carbocation stability is actually what governs the reaction rate, but I cant figure out why. Is the idea that the lower the energy of the carbocation intermediate, the lower the energy of the first transition state (Hammond postulate maybe)? I'm confused about this as I read on Chemlibre that "the Hammond postulate suggests that the activation energy of the rate-determining first step will be inversely proportional to the stability of the carbocation intermediate" which seems to suggest that the higher the energy of the intermediate, the lower the energy of the transition state (which is wrong). Any help would be appreciated.
https://preview.redd.it/luosip80td461.jpg?width=606&format=pjpg&auto=webp&s=e60b8b6c87b4d31abb1dbf86da84bfa0de7d6114
An asymmetric allylation reaction of isatins/ketimines with N‐propargylamide is reported that gives access to alkylideneoxazolines mainly in optically pure form. The key alkylgold intermediate, which possesses allylgold reactivity, has been confirmed by X‐ray crystallographic analysis. The asymmetric formal hetero‐ene reaction of this species, involving a dearomatization process is enabled with the assistance of a quinine‐derived squaramide catalyst.
Abstract
An unprecedented catalytic asymmetric allylation of isatins and isatin‐derived ketimines is reported enabled by a gold and chiral organocatalyst cooperative catalysis strategy. This method offers expeditious access to chiral 2,5‐disubsituted alkylideneoxazolines containing vicinal stereogenic centers, mainly in optically pure form, and which are otherwise impossible to access. Mechanistic evidence reveals the presence of an alkylgold intermediate, and an X‐ray crystal structure of the allylgold species illuminates its unique stability and reactivity. An asymmetric formal hetero‐ene reaction of this gold intermediate, involving a dearomatization process, is enabled with assistance of a quinine‐derived squaramide catalyst. This novel discovery extends the synthetic applications of gold complexes and the versatility of gold catalysis.
https://ift.tt/2HT3OCW
Journal of the American Chemical SocietyDOI: 10.1021/jacs.0c12498
Yaping Fang, Kang Bao, Peng Zhang, Hongting Sheng, Yapei Yun, Shu-Xian Hu, Didier Astruc, and Manzhou Zhu
https://ift.tt/3pag7vt
This review presents a survey of recent examples of fragment coupling reactions that form carbon–carbon bonds via carbanionic or free radical intermediates in total synthesis. The aim is to identify extensible lessons from each example that might be useful to students in the field. Powerful advances in the generation and application of carbanionic and free radical intermediates in complex settings are highlighted.
Abstract
Fragment coupling reactions that form carbon–carbon bonds are valuable transformations in synthetic design. Advances in metal‐catalyzed cross‐coupling reactions in the early 2000s brought a high level of predictability and reliability to carbon–carbon bond constructions involving the union of unsaturated fragments. By comparison, recent years have witnessed an increase in fragment couplings proceeding via carbanionic and open‐shell (free radical) intermediates. The latter has been driven by advances in methods to generate and utilize carbon‐centered radicals under mild conditions. In this Review, we survey a selection of recent syntheses that have implemented carbanion‐ or radical‐based fragment couplings to form carbon–carbon bonds. We aim to highlight the strategic value of these disconnections in their respective settings and to identify extensible lessons from each example that might be instructive to students.
https://ift.tt/2ZsQVnX
Strikingly different reactivity of vanadium and cobalt cationic clusters towards methanol in a low‐pressure collision cell is observed by mass spectrometry. Metastable or kinetically trapped reaction intermediates of the methanol reaction with vanadium cationic clusters are verified, and their structures are proposed by exploring the reaction pathways using density functional theory calculations.
Abstract
A mass spectrometric study of the reactions of vanadium cationic clusters with methanol in a low‐pressure collision cell is reported. For comparison, the reaction of methanol with cobalt cationic clusters was studied. For vanadium, the main reaction products are fully dehydrogenated species, and partial dehydrogenation and non‐dehydrogenation species are observed as minors, for which the relative intensities increase with cluster size and also at low cluster source temperature cooled by liquid nitrogen; no dehydrogenation products were observed for cobalt clusters. Quantum chemical calculations explored the reaction pathways and revealed that the fully dehydrogenation products of the reaction between V n+ and methanol are V n (C)(O)+, in which C and O are separated owing to the high oxophilicity of vanadium. The partial dehydrogenation and non‐dehydrogenation species were verified to be reaction intermediates along the reaction pathway, and their most probable structures were proposed.
https://ift.tt/2IHt2Vl
Nature Chemistry, Published online: 18 November 2020; doi:10.1038/s41557-020-00590-1
Publisher Correction: Exploiting attractive non-covalent interactions for the enantioselective catalysis of reactions involving radical intermediates
https://ift.tt/3lLAkpq
Nature Chemistry, Published online: 19 October 2020; doi:10.1038/s41557-020-00561-6
The past decade has seen unprecedented growth in the development of chemical methods that proceed by mechanisms involving radical intermediates, but controlling absolute stereochemistry has been a longstanding challenge in this area. This Review Article examines how attractive non-covalent interactions between a chiral catalyst and the substrate can exert enantiocontrol in radical reactions.
https://ift.tt/348Stav
Journal of the American Chemical SocietyDOI: 10.1021/jacs.0c07179
https://ift.tt/2RZ0PdM
Zeolite channel geometry–reaction intermediate relationships during the methanol‐to‐hydrocarbon process were identified using advanced solid‐state NMR spectroscopy. As described by M. Baldus, B. M. Weckhuysen, and co‐workers in their Research Article (DOI: https://doi.org/10.1002/anie.20200913910.1002/anie.202009139), the more extended straight zeolite channels promote the aromatic cycle, while the more constrained sinusoidal zeolite channels favor the olefin cycle.
https://ift.tt/2FUa0JP
Metal‐catalyzed C‐N bond formation reactions via acylnitrene transfer have recently attracted much attention, but direct detection of the proposed acylnitrenoid/acylimido M(NCOR) (R = aryl or alkyl) species in these reactions poses a formidable challenge. Herein we report on Ru(NCOR) intermediates in C‐N bond formation catalyzed by [Ru IV (Por)Cl 2 ]/N 3 COR, a catalytic method applicable to aziridine/oxazoline formation from alkenes, amination of substituted indoles, α‐amino ketone formation from silyl enol ethers, amination of C(sp 3 )‐H bonds, and functionalization of natural products and carbohydrate derivatives (up to 99% yield). Experimental studies including HR‐ESI‐MS and EPR measurements, coupled with DFT calculations, lend evidence for the formulation of the Ru(NCOR) acylnitrenoids as a Ru V ‐imido species.
https://ift.tt/3geiGdY
Azolium cumulenolates are a special type of intermediates in N‐heterocyclic carbene catalysis. They contain elongated linear structures with three contiguous C=C bonds and sterically unhindered α‐carbon. These structure features make it difficult to develop enantioselective reactions for these intermediates. Here we disclose the first carbene‐catalyzed highly enantioselective addition reactions of azolium cumulenolates. The reaction starts with alkynals as the precursors for azolium cumulenolate intermediates that undergo enantioselective addition to activated ketones. From the same set of substrates, both allene and spirooxindole products can be obtained with high yields and excellent enantioselectivities. The allene moieties in our optically enriched products carry rich reactivities and can be transformed to diverse molecules. The spirooxindole scaffolds in our products are important structural motifs in natural products and medicines.
https://ift.tt/3mvo4L8
Elucidating hydrogen oxidation reaction (HOR) mechanisms in alkaline conditions is vital for understanding and improving the efficiency of anion‐exchange membrane fuel cells (AEMFCs). However, uncertainty remains around the alkaline HOR mechanism due to a lack of direct in situ evidence of the reaction intermediates. Herein, in situ electrochemical surface‐enhanced Raman spectroscopy (SERS) and density functional theory (DFT) calculations were used to study HOR processes on both PtNi alloy and pure Pt surfaces. Spectroscopic evidence indicates that adsorbed hydroxyl species (OH ad ) were directly involved in HOR processes in alkaline conditions on the PtNi alloy surface. However, OH ad species were not observed on the surface of pure Pt during the HOR. We show that Ni doping promoted hydroxyl adsorption on the Pt‐alloy catalytic surface, improving the HOR activity. DFT calculations also suggest that the free energy was decreased by hydroxyl adsorption. Thus, we provide direct evidence of the presence of the OH ad intermediate species on an oxophilic metal surface during the HOR and deduce its important role in improving the HOR activity and rate. Consequently, tuning OH adsorption by designing bifunctional catalysts is an efficient method for promoting HOR activity.
https://ift.tt/3gTpOuJ
An asymmetric allylation reaction of isatins/ketimines with N‐propargylamide is reported that gives access to alkylideneoxazolines mainly in optically pure form. The key alkylgold intermediate, which possesses allylgold reactivity, has been confirmed by X‐ray crystallographic analysis. The asymmetric formal hetero‐ene reaction of this species, involving a dearomatization process is enabled with the assistance of a quinine‐derived squaramide catalyst.
Abstract
An unprecedented catalytic asymmetric allylation of isatins and isatin‐derived ketimines is reported enabled by a gold and chiral organocatalyst cooperative catalysis strategy. This method offers expeditious access to chiral 2,5‐disubsituted alkylideneoxazolines containing vicinal stereogenic centers, mainly in optically pure form, and which are otherwise impossible to access. Mechanistic evidence reveals the presence of an alkylgold intermediate, and an X‐ray crystal structure of the allylgold species illuminates its unique stability and reactivity. An asymmetric formal hetero‐ene reaction of this gold intermediate, involving a dearomatization process, is enabled with assistance of a quinine‐derived squaramide catalyst. This novel discovery extends the synthetic applications of gold complexes and the versatility of gold catalysis.
https://ift.tt/2Kk93fY
Detection and characterization of fleeting reaction intermediates and active sites are crucial for molecular‐level knowledge of catalysis; insight that is required to understand the catalytic mechanisms, and to design novel high performance catalysts. We report a mass spectrometric study of the reactions of 3d early transition metal (vanadium, [Ar]3d 3 4s 2 ) cationic clusters with methanol in a low‐pressure collision cell. For comparison, the reaction of methanol with 3d late transition metal (cobalt, [Ar]3d 7 4s 2 ) cationic clusters were studied as well. In the vanadium case, the main reaction products are fully dehydrogenated species, and partial dehydrogenation and non‐dehydrogenation species are observed as minors, for which the relative intensities increase with cluster size and also at low cluster source temperature cooled by liquid nitrogen; while no dehydrogenation products have been observed for cobalt clusters. That demonstrates the strikingly different reactivity of vanadium and cobalt cationic clusters towards methanol. Quantum chemical calculations explored the reaction pathways and revealed that the fully dehydrogenation products of the reaction between V n + and methanol are V n (C)(O) + , in which C and O are separated due to the high oxophilicity of vanadium. The partial dehydrogenation and non‐dehydrogenation species observed in the experiment are verified to be reaction intermediates along the reaction pathway, and their most probable structures have been proposed.
https://ift.tt/2IHt2Vl
An unprecedented catalytic asymmetric allylation of isatins and isatin‐derived ketimines enabled by gold and chiral organocatalyst cooperative catalysis strategy is reported. This method offers expeditious access to chiral 2,5‐disubsituted alkylideneoxazolines containing vicinal stereogenic centers, mainly in optically pure form and otherwise impossible to access. Mechanistic evidence revealing the alkylgold intermediate, especially its X‐ray crystal structure, illuminates its unique stability and reactivity as an allylgold species. An asymmetric formal hetero‐ene reaction of this gold intermediate involving a dearomatization process is enabled with assistance of quinine‐derived squaramide catalyst. This novel discovery extends the synthetic application of gold‐complex and versatility of gold catalysis.
https://ift.tt/2HT3OCW
This review presents a survey of recent examples of fragment coupling reactions that form carbon–carbon bonds via carbanionic or free radical intermediates in total synthesis. The aim is to identify extensible lessons from each example that might be useful to students in the field. Powerful advances in the generation and application of carbanionic and free radical intermediates in complex settings are highlighted.
Abstract
Fragment coupling reactions that form carbon–carbon bonds are valuable transformations in synthetic design. Advances in metal‐catalyzed cross‐coupling reactions in the early 2000s brought a high level of predictability and reliability to carbon–carbon bond constructions involving the union of unsaturated fragments. By comparison, recent years have witnessed an increase in fragment couplings proceeding via carbanionic and open‐shell (free radical) intermediates. The latter has been driven by advances in methods to generate and utilize carbon‐centered radicals under mild conditions. In this Review, we survey a selection of recent syntheses that have implemented carbanion‐ or radical‐based fragment couplings to form carbon–carbon bonds. We aim to highlight the strategic value of these disconnections in their respective settings and to identify extensible lessons from each example that might be instructive to students.
https://ift.tt/2ZsQVnX
