Palladium(II)-Catalyzed Enantioselective Arylation of Unbiased Methylene C(sp<sup>3</sup>
)−H Bonds Enabled by a 2-Pyridinylisopropyl Auxiliary and Chiral Phosphoric Acids
作者:Sheng-Yi Yan、Ye-Qiang Han、Qi-Jun Yao、Xing-Liang Nie、Lei Liu、Bing-Feng Shi
DOI:10.1002/anie.201804197
日期:2018.7.16
Enantioselective functionalizations of unbiased methylene C(sp3)−H bonds of linear systems by metal insertion are intrinsically challenging and remain a largely unsolved problem. Herein, we report a palladium(II)‐catalyzedenantioselectivearylation of unbiased methylene β‐C(sp3)−H bonds enabled by the combination of a strongly coordinating bidentate PIP auxiliary with a monodentate chiral phosphoric
Online Hourly Determination of 62 VOCs in Ambient Air: System Evaluation and Comparison with Another Two Analytical Techniques
作者:Nieves Durana、Marino Navazo、Lucio Alonso、José A. García、Juan L. Ilardia、M. Carmen Gómez、Gotzon Gangoiti
DOI:10.1080/10473289.2002.10470857
日期:2002.10
an automatic gas chromatograph (AGC). This system was used to monitor 62 volatile organic compounds (VOCs) in urban air in the Basque Country, Spain. The nonpolar compounds (C2-C10) identified-paraffins, olefins, aromatics, and chlorinated compounds-accounted for 88% of the mass of total non-methane hydrocarbons (TNMHCs) in ambientair. The evaluation of linearity, precision, detection limits (DLs)