Scandium(III) trifluoromethanesulfonate-catalysed reductive Friedel–Crafts benzylation of aromatic compounds using arenecarbaldehydes and propane-1,3-diol
摘要:
Scandium(III) trifluoromethanesulfonate catalyses the Friedel-Crafts benzylation of aromatic compounds with arenecarbaldehydes and propane-1,3-diol to produce, through a clean redox process, diarylmethanes in high to excellent yields.
Derivatization and mass spectrometric investigations of substituted benzeneboronic acids. The use of linked scanning during gas chromatography mass spectrometry
作者:Colin Longstaff、Malcolm Edward Rose
DOI:10.1002/oms.1210171010
日期:1982.10
AbstractSubstituted benzeneboronic acids are important intermediates in the synthesis of support matrices for affinity chromatography but their analysis by mass spectrometry is hindered by thermal reactions in the ion source. A simple derivatization with 1,2‐ or 1,3‐diols removes this difficulty and imparts sufficient volatility for application of gas chromatography/mass spectrometry. The mass spectra of the resulting boronate esters are discussed with reference to high resolution measurements, isotope labelling studies and observation of metastable ions. ortho Substituents are shown to interact strongly during fragmentation. Linked scanning at constant B/E was used to characterize fragmentation pathways and the compatibility of linked scanning and GC/MS is reported.
Collisionally activated mass spectra of [MH] ions of polyhydroxy and hydroxy ether compounds
作者:William C. Brumley、Denis Andrzejewski、James A. Sphon
DOI:10.1002/oms.1210230309
日期:1988.3
AbstractCollision‐induced decomposition/mass‐analyzed ion kinetic energy or collisionally activated mass spectra of [M − H]− ions of polyhydroxy compounds and other alcohols and ethers are reported. The [M − H]− ion of each compound is produced under OH− negative ion chemical ionization mass spectrometric conditions. Characteristic fragmentations are observed that include production of [M − H − 2]−, [M − H − 18]− and [M − H − 32]− ions. Certain other fragment ions in the collisionally activated mass spectra make it possible to distinguish among structural isomers. In polyhydroxy compounds, fragmentation increases as the number of hydroxyl groups increase, and carbon‐carbon bond cleavage becomes favored.
THEOPOLD, K. H.;BERGMAN, R. G., ORGANOMETALLICS, 1982, 1, N 12, 1571-1579