Group 13 exchange and transborylation in catalysis

• Dominic R. Willcox and
• Stephen P. Thomas

Beilstein J. Org. Chem. 2023, 19, 325–348, doi:10.3762/bjoc.19.28

• NaH in place of LiAlH4 gave moderate yields of the hydroboration product, however, comparison of the rates of reaction showed the aluminium had an active catalytic role (Scheme 20) [56]. Shi et al. reported that triethylaluminium catalysed the hydroboration of alkenes, under similar conditions to

Recommendations for performing measurements of apparent equilibrium constants of enzyme-catalyzed reactions and for reporting the results of these measurements

• Robert N. Goldberg,
• Robert T. Giessmann,
• Peter J. Halling,
• Carsten Kettner and
• Hans V. Westerhoff

Beilstein J. Org. Chem. 2023, 19, 303–316, doi:10.3762/bjoc.19.26

• constants and certain enzyme kinetics parameters via the Haldane relationships. These relationships are discussed in references [10][36] and, in fact, values of K′ have been obtained for a fair number of enzyme-catalyzed reactions by measuring rates of reaction and obtaining the enzyme kinetic parameters

Mechanistic studies of the solvolysis of alkanesulfonyl and arenesulfonyl halides

• Malcolm J. D’Souza and
• Dennis N. Kevill

Beilstein J. Org. Chem. 2022, 18, 120–132, doi:10.3762/bjoc.18.13

• the removal of (as chloride ion), a chlorine attached to a carbon. Robertson and co-workers devised a system for a very accurate determination of rates of reaction by following changes in conductivity, with very precise temperature control. In this way, it was possible to observe systematic deviations

• specific rates of reaction with solvent water and the overall value with added hydroxide ion suggested [14], but does not demand, a unimolecular SN1 pathway [28]. Overall, it was concluded [28] that the hydrolyses of both the methane- and benzenesulfonyl chlorides usually involve an SN2 pathway. In a

• ] studied the solvolysis of 2,4,6-trimethylbenzenesulfonyl chloride in a mixture of water with acetone, acetonitrile, dioxane, ethanol or methanol in terms of rates of reaction and also product selectivities for the binary hydroxylic solvents, where both of the components (usually water plus an alcohol

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

• been demonstrated to yield superior results to batch. Higher yields and rates of reaction, and greater selectivities can often be achieved in flow. For example, the rate of the aldol reaction of a silyl enol ether 13 with 4-bromobenzaldehyde (14) showed a marked increase upon transposition to flow [87

Biochemistry of fluoroprolines: the prospect of making fluorine a bioelement

• Vladimir Kubyshkin,
• Rebecca Davis and
• Nediljko Budisa

Beilstein J. Org. Chem. 2021, 17, 439–460, doi:10.3762/bjoc.17.40

The cyclopropylcarbinyl route to γ-silyl carbocations

• Xavier Creary

Beilstein J. Org. Chem. 2019, 15, 1769–1780, doi:10.3762/bjoc.15.170

• trans to trimethylsilyl) were all solvolyzed in CD3CO2D and results are shown in Scheme 14. Since the triflate 69 was highly reactive and could not be isolated in pure form, the mesylate derivative 75 was used in kinetic studies that were carried out in the 40–60 °C range. Rates of reaction of mesylate

Conformational preferences of α-fluoroketones may influence their reactivity

• Graham Pattison

Beilstein J. Org. Chem. 2017, 13, 2915–2921, doi:10.3762/bjoc.13.284

• competition experiments. A competition experiment between two substrates stopped at low conversion (<20%) provides a good approximation for the relative initial rates of reaction of the two substrates through measurement of the relative amounts of the two products formed. These competition reactions should

The difluoromethylene (CF₂) group in aliphatic chains: Synthesis and conformational preference of palmitic acids and nonadecane containing CF₂ groups

• Yi Wang,
• Ricardo Callejo,
• Alexandra M. Z. Slawin and
• David O’Hagan

Beilstein J. Org. Chem. 2014, 10, 18–25, doi:10.3762/bjoc.10.4

• that it can accommodate angle strain. For example CF2 compounds display an apparent Thorpe–Ingold effect relative to CH2 in ring closing metathesis reactions (RCM) to cycloheptene [8]. Comparison of the rates of reaction with different substituents at the C-5 position of the diene precursors 1a–d

3-Pyridinols and 5-pyrimidinols: Tailor-made for use in synergistic radical-trapping co-antioxidant systems

• Luca Valgimigli,
• Daniele Bartolomei,
• Riccardo Amorati,
• Evan Haidasz,
• Jason J. Hanthorn,
• Susheel J. Nara,
• Johan Brinkhorst and
• Derek A. Pratt

Beilstein J. Org. Chem. 2013, 9, 2781–2792, doi:10.3762/bjoc.9.313

• [11][13]. As is the case for phenols, 3-pyridinols and 5-pyrimidinols can be substituted with electron-donating groups to weaken their O–H bonds and increase their rates of reaction with peroxyl radicals in a predictable fashion [11]. Based on these facts, we surmised that 3-pyridinols and 5

A chemist and biologist talk to each other about caged neurotransmitters

• Graham C.R. Ellis-Davies

Beilstein J. Org. Chem. 2013, 9, 64–73, doi:10.3762/bjoc.9.8

• between the two communities to further the creative development and application of these powerful optical probes. Keywords: caged compounds; cell signaling; electrophysiology; neuronal currents; photolabile neurotransmitters; rates of reaction; receptor antagonism; Introduction The first biologically

Alkene selenenylation: A comprehensive analysis of relative reactivities, stereochemistry and asymmetric induction, and their comparisons with sulfenylation

• Vadim A. Soloshonok and
• Donna J. Nelson

Beilstein J. Org. Chem. 2011, 7, 744–758, doi:10.3762/bjoc.7.85

• methyl substituents upon the rates of reaction in several other electrophilic additions to alkenes, including arenesulfenyl chlorides. This is due to steric effects predominating in the former, while electronic effects predominate in the latter. Stereochemical outcomes in the asymmetric reactions of

Kinetic evaluation of the solvolysis of isobutyl chloro- and chlorothioformate esters

• Malcolm J. D’Souza,
• Matthew J. McAneny,
• Dennis N. Kevill,
• Jin Burm Kyong and
• Song Hee Choi

Beilstein J. Org. Chem. 2011, 7, 543–552, doi:10.3762/bjoc.7.62

• could have an impact on any potential steric or electronic effects, due to presence of the isobutyl group, on the specific rates of reaction. In this article we present determinations of the specific rates of reaction for isobutyl chloroformate (iBuOCOCl, 1) at 40.0 °C and of isobutyl chlorothioformate

• order to evaluate the details of the interactions at the transition-state for 1, we statistically analyzed (using Equation 1) the rates of reaction using multiple regression analysis. In all 22 solvents we obtained l = 1.11 ± 0.14, m = 0.43 ± 0.08, R = 0.886, F-test = 35, and c = 0.01 ± 0.10. The poor