3 research outputs found
Adaptation of a Small-Molecule Hydrogen-Bond Donor Catalyst to an Enantioselective Hetero-Diels–Alder Reaction Hypothesized for Brevianamide Biosynthesis
Chiral diamine-derived hydrogen-bond
donors were evaluated for
their ability to effect stereocontrol in an intramolecular hetero-Diels–Alder
(HDA) reaction hypothesized in the biosynthesis of brevianamides A
and B. Collectively, these results provide proof of principle that
small-molecule hydrogen-bond catalysis, if even based on a hypothetical
biosynthesis construct, holds significant potential within enantioselective
natural product synthesis
Adaptation of a Small-Molecule Hydrogen-Bond Donor Catalyst to an Enantioselective Hetero-Diels–Alder Reaction Hypothesized for Brevianamide Biosynthesis
Chiral diamine-derived hydrogen-bond
donors were evaluated for
their ability to effect stereocontrol in an intramolecular hetero-Diels–Alder
(HDA) reaction hypothesized in the biosynthesis of brevianamides A
and B. Collectively, these results provide proof of principle that
small-molecule hydrogen-bond catalysis, if even based on a hypothetical
biosynthesis construct, holds significant potential within enantioselective
natural product synthesis
NMR Chemical Shifts of Trace Impurities: Industrially Preferred Solvents Used in Process and Green Chemistry
The <sup>1</sup>H and <sup>13</sup>C NMR chemical shifts of 48
industrially preferred solvents in six commonly used deuterated NMR
solvents (CDCl<sub>3</sub>, acetone-<i>d</i><sub>6</sub>, DMSO-<i>d</i><sub>6</sub>, acetonitrile-<i>d</i><sub>3</sub>, methanol-<i>d</i><sub>4</sub>, and D<sub>2</sub>O) are reported. This work supplements the compilation of
NMR data published by Gottlieb, Kotlyar, and Nudelman (J. Org. Chem. 1997, 62, 7512) by providing
spectral parameters for solvents that were not commonly utilized at
the time of their original report. Data are specifically included
for solvents, such as 2-Me-THF, <i>n</i>-heptane, and <i>iso</i>-propyl acetate, which are being used more frequently
as the chemical industry aims to adopt greener, safer, and more sustainable
solvents. These spectral tables simplify the identification of these
solvents as impurities in NMR spectra following their use in synthesis
and workup protocols