Traditional radical-mediated ring-opening of bicyclo[1.1.0]butanes (BCBs) for cyclobutane synthesis suffers from poor diastereoselectivity. Although few reports on BCB via polar mechanisms are available, the Lewis acid-catalyzed diastereoselective BCBs using carbon nucleophiles is still underdeveloped. Herein, we report a mild and Bi(OTf)3-catalyzed employing 2-naphthols. The anticipated carbofunctionalized trisubstituted cyclobutanes were obtained bicoordinated bismuth complex products...

Bicyclo[1.1.0]butanes (BCBs), strained carbocycles comprising two fused cyclopropane rings, have become well-established building blocks in organic synthesis, medicinal chemistry, and chemical biology due to their diverse reactivity profile with radicals, nucleophiles, cations, carbenes. The constraints of the bicyclic ring system confer high p-character on interbridgehead C–C bond, leading this broad reaction profile; however, use BCBs pericyclic processes has date been largely overlooked...

The insertion of arynes into the S-N σ-bond sulfenamides allowing synthesis o-sulfanylaniline derivatives with reasonable functional group compatibility is presented. aryne generated from 2-(trimethylsilyl)aryl triflates using CsF in DME was key for success this transition-metal-free thioamination reaction, which involves new C-N and C-S bond formations a single step under mild conditions. Moreover, synthetic potential method demonstrated by antidepressant drug vortioxetine.

A facile synthesis of biologically important S-aryl dithiocarbamates has been demonstrated by the aryne three-component coupling involving CS2 and aliphatic amines. This transition-metal-free mild reaction is scalable operates with good functional group compatibility. Preliminary mechanistic experiments, including density theory studies, are also provided. Moreover, 3-triflyloxybenzynes, a unique four-component incorporating tetrahydrofuran was observed.

Abstract A theoretical model is presented that can be used to predict the structure and rate of spread an attached diffusion flame moving over a thermally thin, pyrolyzing combustible placed in gravity-free, quiescent, oxidizing environment. The gas-phase includes steady-state, two-dimensional momentum, energy, species equations while solid-phase consists continuity energy equations, solution which provide boundary conditions for problem. appears as eigenvalue both gas- equations. numerical...

An aryne induced transition-metal-free and mild Sommelet–Hauser rearrangement of tertiary benzylamines for the synthesis α-aryl amino acid derivatives in moderate to good yields with broad substrate scope is presented.

A transition-metal-free, [2,3] sigmatropic rearrangement-annulation cascade of 2-substituted thio/amino acetonitriles with arynes allowing the synthesis 2,4,5-trisubstituted oxazoles under mild conditions has been demonstrated. The key sulfur/nitrogen ylides were generated by initial S/N arylation followed proton transfer, which was selective rearrangement involving -CN moiety and a subsequent annulation to afford desired products in reasonable yields.

The three-component coupling of tertiary amines, arynes, and aryl selenium bromide or diaryl diselenide as an electrophilic source allowing the synthesis 2-selanyl aniline derivatives is reported. This aminoselenation reaction arynes installs a C-N C-Se bond under mild conditions, products are formed in moderate to good yields. compatible with various functional groups, preliminary studies on mechanism also provided.

The synthetic utility of NaN3 as the azide component in [3 + 2] annulation with arynes generated from 2-(trimethylsilyl)aryltriflates resulting transition-metal-free synthesis N-H and N-aryl benzotriazoles has been demonstrated. Using CsF fluoride source CH3CN, are formed high selectivity instead expected azidobenzene. Interestingly, using KF THF solvent an open-flask reaction. Moreover, a method for N1-arylation benzotriazole is also presented.

The synthetic potential of thiophenols as a protic nucleophilic trigger in the transition-metal-free and Grignard-reagent-free three-component coupling involving arynes is demonstrated. Employing aldehydes third component, reaction allowed mild broad scope synthesis 2-arylthio benzyl alcohol derivatives good yields. Moreover, selenophenol could be used trigger, activated ketones component this reaction.

Abstract Temperature and velocity fields in a downward flame spread over flat, solid fuels gravitational field are numerically simulated compared with available experimental measurements simplified theory. The two-dimensional steady numerical model solves the mass, energy, species-mass, momentum equations gaseous phase energy equation includes gas-phase pyrolysis kinetics, gas surface radiation feedback. published results include measured temperature profiles, regression data, visible images...

In opposed-flow flame spread over solid fuels, an indefinite increase in flow velocity eventually leads to extinguishment. While the chemical time is independent of velocity, residence oxidizer at leading edge inversely proportional and, therefore, a completion between two situation where finite-rate kinetics dominate behavior, Their ratio, non-dimensional Damkohler number, known capture this effect and has been used correlate rate. Although these correlations explain behavior observed...

The synthetic potential of KI as the iodide source in aryne three-component coupling has been demonstrated using aldehydes third component. This mild and transition-metal-free reaction allowed straightforward synthesis 2-iodobenzyl alcohols moderate to good yields with functional group compatibility. Moreover, KBr KCl could be used nucleophilic trigger this multicomponent (MCC) N-methylisatin CO2 electrophilic components.

Results from recently conducted experiments on flame spread over a thin cellulosic fuel in quiescent, microgravity environment of 50/50 volumetric mixture oxygen and nitrogen (oxygen mass fraction 0.53) at three different pressures—101, 152, 203 kPa (1, 1.5, 2.0 atm)—are analyzed. The results are compared with established theoretical two computational models: one that includes gas-phase radiation, does not. rate behavior experiment, i.e., an increase pressure, is consistent the model...