Development of Biomimetic Synthesis of Propindilactone G^†

Abstract

of main observation and conclusion The natural product propindilactone G is a complex Schisandra nortriterpenoid with a unique 5/5/7/6/5 pentacyclic framework. This full paper describes the development of concise biomimetic synthesis of propindilactone G from a known steroid lactone. The key C19-OH intermediate was synthesized via Breslow and Suárez radical remote C-H functionalizations. Wagner-Meerwein rearrangement was subsequently utilized for the expansion of the B ring. To invert the configuration of the C10 tertiary alcohol, an intramolecular peroxide cyclization catalyzed by BF3•Et2O was devised. The 5/5 fused lactone system was then assembled in a biomimetic transesterification/oxa-Michael addition sequence. Our work should provide experimental support for the proposed biosynthetic pathway and facilitate investigation of the biological activities of propindilactone G.

Copper-indium bimetallic catalysts for the selective electrochemical reduction of carbon dioxide

“…Currently, precious metals such as gold and palladium can effectively convert CO2 into CO or formate [19][20][21][22]; however, their high cost greatly limits their application in CO2RR. Indium and its alloys have already been proven to possess high catalytic properties for CO2RR to afford formate with a low cost [23][24][25][26][27][28][29]. However, the current density and selectivity of these catalysts are unsatisfactory at low overpotentials.…”

Gram-Scale Synthesis of Bufospirostenin A by a Biomimetic Skeletal Rearrangement Approach

“…Alternatively, enzymatic oxidation at C1 of 5 would give 7 , and subsequent 1,2-migration of C5 from C10 to C1 would afford 5(10→1) abeo -steroid 10 . The pioneering synthesis of cortistatin A by Baran and co-workers, along with our previous biomimetic syntheses of cyclocitrinol ( 1 ) and propindilactone G ( 2 ), validated the proposed biogenetic pathways leading to 8 and 9 . However, experimental evidence for the proposed pathway leading to 10 has yet to be established.…”

Effects of metal promoters in bimetallic catalysts in hydrogenolysis of lignin derivatives into value‐added chemicals

“…The scanning electron microscope (SEM) images with particle size distributions and X‐ray energy dispersive spectrometry (XEDS) analysis of Ni/AC and Ni−Ru/AC catalysts were exhibited in Figure 16. For the Ni−In catalyst, the selectivity of BTX (toluene, phenol and ethylbenzene) and cyclohexane was enhanced as a result of the geometric and electronic effect in the HDO of anisole [97] …”