Synthesis of norlignans and in vitro inhibitory activity of antigen-induced degranulation

Nickel-Catalyzed Ligand-Controlled Regioselective Allylic Alkenylation of Allylic Alcohols with Easily Accessible Alkenyl Boronates: Synthesis of 1,4-Dienes

A nickel-catalyzed direct reaction of allylic alcohols with easily accessible alkenyl boronates has been developed, which provides valuable 1,4-dienes with high regio- and stereoselectivity in good to excellent yields, wide substrate scope, and functional group compatibility. The catalytic system simply consists of Ni(cod)2 as the catalyst and a ligand, without a need for a base and alcohol activator in most cases. The proper choice of ancillary ligands is highly important for this reaction. Depending on the substitution pattern of allylic alcohols and/or alkenyl boronates, different ligands were used for improving the reaction efficiency.

Syntheses and in Vitro Antiplasmodial Activity of Aminoalkylated Chalcones and Analogues

A series of readily synthesized and inexpensive aminoalkylated chalcones and diarylpropane analogues (1-55) were synthesized and tested against chloroquinone-sensitive (D10 and NF54) and -resistant (Dd2 and K1) strains of Plasmodium falciparum. Hydrogenation of the enone to a diarylpropane moiety increased antiplasmodial bioactivity significantly. The influence of the structure of the amine moiety, A-ring substituents, propyl vs ethyl linker, and chloride salt formation on further enhancing antiplasmodial activity was investigated. Several compounds have IC₅₀ values similar to or better than chloroquine (CQ). The most active compound (26) had an IC₅₀ value of 0.01 μM. No signs of resistance were detected, as can be expected from compounds with structures unrelated to CQ and other currently used antimalarial drugs. Toxicity tests (in vitro CHO cell assay) gave high SI indices.

Concise Total Synthesis of 1,3-Diphenylpropane Derivatives Griffithanes A, B and F

Concise and efficient total syntheses of diarylpropanes griffithane A, B and F, isolated from Combretum griffithii, have been accomplished from methoxybenzaldehyde. The Claisen–Schmidt condensation between aldehyde and acetophenone was applied to form chalcone as a key step. The structures of chalcones are confirmed by crystal X-ray crystallography.