In this report, three studies are presented that utilize computations to predict transformations, identities, and properties of environmental organic molecules. Each study shows how computations can lead to models of chemical behavior. The importance of this research is rooted in the need for understanding how human behavior and health intersect...
Xanthohumol [XN, (E)-6´-methoxy-3´-(3-methylbuten-2-yl)-2´,4´,4´´-trihydroxychalcone], the principal prenylated chalcone from hops, and its 2,3-dihydro- (DXN) and O6-desmethyl-2,3-dihydro- (DDXN) congeners, are of potential utility for the amelioration of metabolic syndrome; however, their complex bioactivity profiles cannot be properly studied and understood without access to appropriately produced synthetic materials.
In the first part of...
Part 1: A Diels-Alder Approach to the Synthesis of Novel Analogues of the Natural
Product Siamenol
Due to the prevalence of biaryl motifs in natural product synthesis, the Carter
research group has been exploring the utility of a Diels-Alder approach to biaryl
synthesis. The Diels-Alder approach involves a [4+2] cycloaddition...
7,7'-Dihydroxy-8,8'-biquinolyl (azaBINOL) was prepared from 7-hydroxyquinoline via N,N-dimethyl O-quinol-7-yl carbamate by directed ortho-metallation followed by FeCl₃-mediated oxidative coupling of the 8-lithioquinoline intermediate. Saponification of the resulting dicarbamate provided crystalline (±)-azaBINOL in 56% overall yield. 6,6'-Bis(dimethylaminocarbonyl)-7,7'-dihydroxy-8,8´-biquinolyl was prepared from the same dicarbamate by a double anionic-Fries rearrangement in 43% yield. 7,7'-Bis(diethylamino-carbonyloxy)-6,6'-diiodo-8,8´-biquinolyl...
Sulfoxide-ligand exchange (SLE) and asymmetric halogen-metal exchange (AHME) processes were separately examined for the enantioselective synthesis of functionalized alpha-haloalkylmetal (carbenoid) reagents. Carbenoids derived from SLE were used to effect stereospecific reagent-controlled homologation (StReCH) of boronic esters and those generated via AHME were engaged in Darzens-type chemistry with aldehydes.
Abstract for...
In this report, three studies are presented that aid in the development of drug discovery and their synthesis. In each, the importance of the marriage between computations and experiments is highlighted. Continued efforts in this vein are essential for future efforts towards improving human health.
The first case study investigated...
Many D2d-symmetric 2,2',6,6'-tetrasubstituted biphenyls are
readily prepared via net oxidative dimerization of appropriate
1,3-disubstituted benzenes. Conversion of such proprochiral
compounds to useful C2-symmetric chiral biphenyls requires
formal replacement of two substituents on opposing aryl ring
units with alternate groups. This under exploited
desymmetrization tactic has been demonstrated for the
generation...
Two distinct strategies were explored for the enantioselective synthesis of α-heteroatom substituted alkyl boronic esters by stereoselective reagent-controlled homologation using transient chiral carbenoid reagents CHYMX (Y = heteroatom, X = nucleofuge, M = electrofuge). In the first case, a stereospecific reagent-controlled homologation (sStReCH) approach to α-alkoxyalkylboronates using α-metalated S,O- and...