01696nas a2200205 4500008004100000022001400041245020400055210006900259260023400328300001400562490000700576520064000583653002301223653001901246653002201265653003101287100001901318700002101337856013201358 2012 eng d a0033-454500aStereoselective construction of 5,11-methanomorphanthridine and 5,10b-phenanthridine structural frameworks: total syntheses of (+/-)-pancracine, (+/-)-brunsvigine, (+/-)-maritidine, and (+/-)-crinine0 aStereoselective construction of 511methanomorphanthridine and 51 a104 TW ALEXANDER DR, PO BOX 13757, RES TRIANGLE PK, NC 27709-3757 USAbVirginia Taylor; Astra Zeneca; Chem Sci Scotland; Eisai; EPSRC; Glasgow City Council; GSK; IUPAC; Pfizer; Scottish Enterprise; Syngenta; Univ StrathclydecMAY a1597-16190 v843 a

The core structure of the complex pentacyclic 5,11-methanomorphanthridine skeleton and the vicinal quaternary and tertiary stereocenters of the 5,10b-phenanthridine skeleton are constructed stereospecifically in one step employing intramolecular 1,3-dipolar cyclo addition of a nonstabilized azomethine ylide (AMY) generated by the sequential double desilylation of appropriate bis-trimethylsilylmethyl amines using Ag(I)F as a single-electron oxidant. The strategy is successfully applied for the total synthesis of biologically active alkaloids such as (+/-)-pancracine, (+/-)-brunsvigine, (+/-)-maritidine, and (+/-)-crinine.

10aalkaloid synthesis10acycloadditions10aorganic synthesis10astereocontrolled synthesis1 aPandey, Ganesh1 aGadre, Smita, R. uhttps://library.ncl.res.in/content/stereoselective-construction-511-methanomorphanthridine-and-510b-phenanthridine-structural-001539nas a2200205 4500008004100000022001400041245013300055210006900188260000800257300001100265490000700276520080700283653001501090653002001105653002201125653002001147100001601167700002101183856012901204 2021 eng d a0040-402000aTotal synthesis of twelve membered resorcyclic acid lactones, (R)-penicimenolide A, (R)-resorcyclide and (R)-dihydroresorcyclide0 aTotal synthesis of twelve membered resorcyclic acid lactones Rpe cAPR a1320590 v853 a

Resorcyclic Acid Lactones or RALs are a class of fungal secondary polyketides isolated from a variety of fungal strains like Lasiodiplodia theobromae, Penicillium sp., Syncephalastrum racemosum etc. This class of macrocyclic lactones are found to exhibit a broad spectrum of biological activities and are of significant synthetic importance. Herein, we report the first total synthesis of (R)-penicimenolide A, twelve membered RAL (RAL12) isolated from Penicillium sp. (NO. SYP-F-7919). Besides, we also report the total synthesis of two other members, namely, (R)-trans-resorcyclide and (R)-dihydroresorcyclide. In the course of synthesis, we have utilized ring closing metathesis (RCM) as the key step in constructing the core macrolactone scaffold. (C) 2021 Elsevier Ltd. All rights reserved.

10aMacrocycle10aNatural product10aorganic synthesis10aTotal synthesis1 aDas, Pronay1 aReddy, Srinivasa uhttps://library.ncl.res.in/content/total-synthesis-twelve-membered-resorcyclic-acid-lactones-r-penicimenolide-r-resorcyclide02048nas a2200229 4500008004100000022001400041245010800055210006900163260000900232300001400241490000700255520125900262653002101521653001001542653002201552100002201574700002201596700002901618700002601647700002001673856012501693 2023 eng d a1463-926200aIron-catalyzed regioselective C-H alkylation of indoles: an additive-free approach in renewable solvent0 aIroncatalyzed regioselective CH alkylation of indoles an additiv cNOV  a9733-97430 v253 a

Alkylated indoles are important motifs in various biologically active molecules and drug candidates. Herein, we report a mild and efficient iron-catalyzed protocol for synthesizing alkylated indoles via C-H bond alkylation of indoles with unactivated alkenes, demonstrating a high level of regioselectivity. The reaction occurs under additive-free, solvent-free (or trace green solvent, 2-MeTHF) and less energy-intensive conditions using a sustainable metal catalyst and provides easy access to privileged alkylated indoles with anti-Markovnikov selectivity. Alkylation is compatible with important functionalities, such as fluoro, chloro, trifluoromethyl, alkenyl, ether, thioether, silyl, and siloxane, including heteroaryl, pyridinyl, carbazolyl, and indolyl moieties (45 examples, up to 96% yield). The developed protocol is very simple, straightforward, and fully accords with the principles of green chemistry. A detailed mechanistic investigation manifests the facile indole's C-H activation at the Fe(0) center, reversible 1,2-insertion of the alkene into the Fe-H bond of a metallacycle, and a turnover-limiting reductive elimination. Alkylated indoles are important motifs in various biologically active molecules and drug candidates.

10aAromatic Ketones10aGreen10aorganic synthesis1 aPradhan, Chandini1 aJagtap, Rahul, A.1 aSamal, Pragnya, Paramita1 aKrishnamurty, Sailaja1 aPunji, Benudhar uhttps://library.ncl.res.in/content/iron-catalyzed-regioselective-c-h-alkylation-indoles-additive-free-approach-renewable