A convenient access to 1,3-disubstituted furo[3,4-b]indoles by acid ion-exchange resin-catalyzed furan formation

Fragment-Based Design, Synthesis, and Biological Evaluation of 1-Substituted-indole-2-carboxylic Acids as Selective Mcl-1 Inhibitors

Based on a known selective Mcl-1 inhibitor, 6-chloro-3-(3-(4-chloro-3,5-dimethylphenoxy)propyl)-1H-indole-2-carboxylic acid, we applied a fragment-based approach to obtain new molecules that extended into the p1 pocket of the BH3 groove and then exhibited binding selectivity for the Mcl-1 over the Bcl-2 protein. After we deconstructed the 1H-indole-2-carboxylic acid from the parental molecule, a benzenesulfonyl was substituted at the 1-position to adopt a geometry preferred for accessing the p1 pocket according to the binding mode of the parental molecule identified by X-ray crystallography. A linear relationship between the free energy of ligand binding (ΔG) and the count of non-hydrogen heavy atoms (HAC) was maintained during the molecular growing to occupy the p1 pocket. Finally, we not only obtained compound 12 with a 7.5-fold selectivity to Mcl-1 (K_i  = 0.48 µM by fluorescence polarization) over Bcl-2 (K_i  = 3.6 µM), but also provided evidence that additional occupation of the p1 pocket is more favorable for Mcl-1 than for Bcl-2 binding, and contributes more to Mcl-1 inhibition than occupation of the p2 pocket. Compound 12 exhibited a selective killing ability on Mcl-1-dependent cancer cells.

One-pot relay catalysis: divergent synthesis of furo[3,4-b]indoles and cyclopenta[b]indoles from 3-(2-aminophenyl)-1,4-enynols

Described herein a divergent strategy for the synthesis of furo[3,4-b]indoles via a sequential Ag(i)/Bi(iii)/Pd(ii) catalysis and cyclopenta[b]indoles via a one-pot Ag(i)/Brønsted acid relay catalysis, starting from the easily accessible 3-(2 aminophenyl)-4-pentenyn-3-ols.

Simple indole alkaloids and those with a nonrearranged monoterpenoid unit

This review summarizes the isolation, structure determination, total syntheses and biological activities of simple indole alkaloids and those with a nonrearranged monoterpenoid unit, with literature coverage from 2012 to 2013.