Two 1‐[6]helicenol derivatives were synthesized by Ni‐catalyzed [2+2+2] cycloaddition on a multigram scale. Both enantiomers of the 1‐[6]helicenols could be efficiently prepared by simple optical resolution. As a synthetic application of helically chiral 1‐[6]helicenols, a novel class of [6]helicene‐based phosphinites was developed; these compounds represent the first examples of helically chiral phosphinite ligands. Up to 90 % ee was obtained for the Pd‐catalyzed asymmetric allylic alkylation reaction.
The
first enantioselective Pictet–Spengler reaction of acyclic
α-ketoesters with tryptamines has been developed. Excellent
yields and enantioselectivity were obtained for the reaction using
chiral imidazoline-phosphoric acid catalysts. Density functional theory
calculations suggested possible transition states that explain the
origin of chiral induction. This process provides an efficient route
for the synthesis of tetrahydro-β-carboline derivatives.
We
designed and synthesized a novel 1,2-deoxy-pyranose and terminal
epoxide methyl substituted derivatives of spliceostatin A using Julia–Kocienski
olefination as a key step. With respect to the biological activity,
the 1,2-deoxy-pyranose analogue of spliceostatin A suppressed AR-V7
expression at the nano level (IC50 = 3.3 nM). In addition,
the in vivo toxicity test showed that the 1,2-deoxy-pyranose
analogue was able to avoid severe toxicity compared to spliceostatin
A.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.