Experimental and Theoretical Investigations of the Bromination of Phenols with β and γ Aliphatic Substituents, including Rings
作者:Jinsong Zhang、Xiao Chang、Erich C. Bowman、Carter J. Holt、Michael W. Lodewyk、Randy M. Miller、Guangming Xia
DOI:10.1021/acs.joc.5b01866
日期:2015.9.18
Bromination reactions of substituted and ring fused phenols were studied by both experiment (t-BuNH-Br) and computation (density functional theory). The outcomes support each other, indicating a clear and predictable regioselective preference among 3,4-bis-alkylated and 3,4-ring-fused phenols.
The present invention relates to a pipette tip comprising a proximal region and a distal region, wherein the proximal region comprises an exterior surface and an annular flange at the proximal terminus of the proximal region, the proximal region comprises a first set of axially oriented ribs and a second set of axially oriented ribs, the ribs of the first set and the second set are circumferentially spaced and alternately spaced around the exterior surface of the proximal region, and ribs of the first set have a maximum thickness greater than the maximum thickness of ribs of the second set.