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Alkyl boronic acids and esters are versatile synthetic intermediates that generally require several steps to synthesize. Three-component alkene arylboration reactions allow for the rapid synthesis of alkyl boronic esters. Herein, we report the base-free aerobic Pd-catalyzed three-component alkene arylboration, which allows direct access, in a single step, to alkyl boronic esters from readily available precursors: aryl boronic acids, alkenes, and bis(pinacol)diboron. This approach allows for the formal insertion of an alkene into an Ar–B bond, and thus, generates an alkyl boronic ester from an aryl boronic acid. The reaction proceeds with both electron-rich and electron-deficient aryl boronic acids as well as strained cyclic, internal, and terminal olefins. The reactions are regioselective: 1,2-arylboration products are formed with strained cyclic alkenes and b-alkyl-styrenes while 1,1-arylboration products are generated from terminal alkenes. Forty-five examples are presented with isolated yields of the resulting alkyl boronic esters ranging from 20-74%, along with several examples demonstrating the synthetic utility of the products. Mechanistic investigations support that the catalytic cycle occurs through direct arylboration of the alkene. Further, p-benzyl intermediates form when possible, and the rate of borylation is increased with electron-rich arenes relative to electron-poor. Finally, we demonstrate that aryl boroxines, generated in situ, are essential for the transformation as they rapidly undergo base-free transmetalation with the proposed palladium peroxo intermediate. 

Ion-neutral coupling is responsible for dissipating energy deposited into the high-latitude ionosphere during geomagnetically active periods. The neutral wind response time, or the ion-neutral coupling efficiency, is not well characterized, with a wide range of reported response times. Additionally, how this coupling efficiency varies with geomagnetic activity level is not well understood, with few studies addressing the impact of geomagnetic activity level on neutral wind response time. In this study, a statistical analysis of the neutral wind response time during substorm periods is performed. We use data from Scanning Doppler Imagers (SDIs) and the Poker Flat Incoherent Scatter Radar (PFISR) to calculate the neutral wind response time using the new weighted windowed time-lagged correlation method. Substorm events were found using SuperMAG substorm lists and All Sky Imagers (ASIs). This statistical analysis resulted in 23 substorm events, with an average response time of $\sim$16 min. To determine the controlling factors of this response time, geomagnetic and ionospheric parameters, such as IMF strength and orientation, SYM/H index, AE index, and electron density, are investigated for the statistical substorm set. A superposed epoch analysis of the parameters is performed to determine average geospace conditions required for fast neutral wind responses. It was found that quiet-time conditions in AE and SYM-H indices, a southward turning of IMF around 1.5 h before substorm onset time, and large electron densities lead to faster neutral wind response times. Based on the geomagnetic indices results, it was suggested that thermospheric pre-conditioning may play a role in neutral wind response times.