@article { ISI:000305742400008, title = {Stereoselective construction of 5,11-methanomorphanthridine and 5,10b-phenanthridine structural frameworks: total syntheses of (+/-)-pancracine, (+/-)-brunsvigine, (+/-)-maritidine, and (+/-)-crinine}, journal = {Pure and Applied Chemistry}, volume = {84}, number = {7}, year = {2012}, note = {23rd International Congress on Heterocyclic Chemistry (ICHC), Glasgow, SCOTLAND, JUL 31-AUG 04, 2011}, month = {MAY}, pages = {1597-1619}, publisher = {Virginia Taylor; Astra Zeneca; Chem Sci Scotland; Eisai; EPSRC; Glasgow City Council; GSK; IUPAC; Pfizer; Scottish Enterprise; Syngenta; Univ Strathclyde}, type = {Article}, address = {104 TW ALEXANDER DR, PO BOX 13757, RES TRIANGLE PK, NC 27709-3757 USA}, abstract = {

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.

}, keywords = {alkaloid synthesis, cycloadditions, organic synthesis, stereocontrolled synthesis}, issn = {0033-4545}, doi = {10.1351/PAC-CON-11-10-12}, author = {Pandey, Ganesh and Gadre, Smita R.} } @article {47402, title = {Total synthesis of twelve membered resorcyclic acid lactones, (R)-penicimenolide A, (R)-resorcyclide and (R)-dihydroresorcyclide}, journal = {Tetrahedron}, volume = {85}, year = {2021}, month = {APR}, pages = {132059}, type = {Article}, abstract = {

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.

}, keywords = {Macrocycle, Natural product, organic synthesis, Total synthesis}, issn = {0040-4020}, doi = {10.1016/j.tet.2021.132059}, author = {Das, Pronay and Reddy, D. Srinivasa} } @article {48957, title = {Iron-catalyzed regioselective C-H alkylation of indoles: an additive-free approach in renewable solvent}, journal = {Green Chemistry }, volume = {25}, year = {2023}, month = {NOV }, pages = {9733-9743}, type = {Journal Article}, abstract = {

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{\textquoteright}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.

}, keywords = {Aromatic Ketones, Green, organic synthesis}, issn = {1463-9262}, doi = {10.1039/d3gc03709f}, author = {Pradhan, Chandini and Jagtap, Rahul A. and Samal, Pragnya Paramita and Krishnamurty, Sailaja and Punji, Benudhar} }