https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

A. Primary Alcohols as Nucleophiles 2931 B. Carboxylates as Nucleophiles 2931 C. Alkylations with Phenols 2932 IV. Nitrogen Nucleophiles in AAA Total Synthesis 2935 A. Alkylamines as Nucleophiles 2935 B. Azides as a Nucleophile 2936 C. Sulfonamide Nucleophiles 2937 D. Imide Nucleophiles 2938 E. Heterocyclic Amine Nucleophiles 2940 V. Sulfur Nucleophiles 2941 VI. Summary and Conclusions 2941 VII. Acknowledgment 2941 VIII. References 2942 I. Considerations for Enantioselective Allylic Alkylation

http://athena.uwindsor.ca/users/j/jlichaa/reference.nsf/54ef3e94e5fe816e85256d6e0063d208/10ff8b04ff3a317885256d88005720f6/$file/cr-2003-103-2921-trost-allylpd.pdf

Asymmetric transition-metal-catalyzed allylic alkylations: applications in total synthesis.

Since the discovery of organic azides by Peter Griess more than 140 years ago, numerous syntheses of these energy-rich molecules have been developed. In more recent times in particular, completely new perspectives have been developed for their use in peptide chemistry, combinatorial chemistry, and heterocyclic synthesis. Organic azides have assumed an important position at the interface between chemistry, biology, medicine, and materials science. In this Review, the fundamental characteristics of azide chemistry and current developments are presented. The focus will be placed on cycloadditions (Huisgen reaction), aza ylide chemistry, and the synthesis of heterocycles. Further reactions such as the aza-Wittig reaction, the Sundberg rearrangement, the Staudinger ligation, the Boyer and Boyer-Aube rearrangements, the Curtius rearrangement, the Schmidt rearrangement, and the Hemetsberger rearrangement bear witness to the versatility of modern azide chemistry.

Organic Azides: An Exploding Diversity of a Unique Class of Compounds

The preparation of urea by Wöhler constituted a landmark achievement in organic chemistry, and it laid the ground for the early days of target-oriented organic synthesis.1 Since then, significant progress has been achieved in this discipline; many powerful single bond forming reactions and asymmetric variants have been developed. These discoveries have paved the way for the stereoselective assembly of complex organic molecules, a task deemed inconceivable by early practitioners. A great many strategies were invented by chemists in order to facilitate the synthesis of complex natural products.2 One avenue in emulating nature’s efficiency would * To whom correspondence should be addressed. E-mail: dennis.hall@ ualberta.ca. † Novartis Institute for Biomedical Research. ‡ Department of Chemistry, University of Alberta. Chem. Rev. 2009, 109, 4439–4486 4439

Natural product synthesis using multicomponent reaction strategies.

13C NMR spectra of pentacyclic triterpenoids--a compilation and some salient features

Purealidins B and C, new bromotyrosine alkaloids from the okinawan marine sponge psammaplysilla purea

Alteramide A, a new tetracyclic alkaloid from a bacterium Alteromonas sp. associated with the marine sponge Halichondria okadai

Ascididemin, a novel pentacyclic aromatic alkaloid with potent antileukemic activity from the Okinawan tunicate Didemnum sp.

We previously designed 1-(3-C-ethynyl-β-d-ribo-pentofuranosyl)uracil (EUrd) as a potential multifunctional antitumor nucleoside antimetabolite. It showed a potent and broad spectrum of antitumor activity against various human tumor cells in vitro and in vivo. To determine the structure−activity relationship, various nucleobase analogues of EUrd, such as 5-fluorouracil, thymine, cytosine, 5-fluorocytosine, adenine, and guanine derivatives, were synthesized by condensation of 1-O-acetyl-2,3,5-tri-O-benzoyl-3-C-ethynyl-α,β-d-ribo-pentofuranose (6) and the corresponding pertrimethylsilylated nucleobases in the presence of SnCl4 or TMSOTf as a Lewis acid in CH3CN followed by debenzoylation. The in vitro tumor cell growth inhibitory activity of these 3‘-C-ethynyl nucleosides against mouse leukemia L1210 and human nasopharyngeal KB cells showed that 1-(3-C-ethynyl-β-d-ribo-pentofuranosyl)cytosine (ECyd) and EUrd were the most potent inhibitors in the series, with IC50 values for L1210 cells of 0.016 and 0.13 μM ...

Nucleosides and nucleotides. 158. 1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)-cytosine, 1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)uracil, and their nucleobase analogues as new potential multifunctional antitumor nucleosides with a broad spectrum of activity.

A series of 4'alpha-C-branched-chain pyrimidine nucleosides was synthesized from 2'-deoxycytidine or uridine. In the 2'-deoxycytidine series, the substituent at the 4'alpha-position affected cytotoxicity against L1210 mouse leukemic cells in vitro in the order Me (23) > CN (22) > C(symbol)CH (21) > CH=CH(2) (19) > Et (24) > CH=CHCl (20). However, uridine and cytidine derivatives with ethynyl and cyano groups at the 4'alpha-position did not show any cytotoxicity. The antiviral activities of these nucleosides against HSV-1, HSV-2, and HIV-1 in vitro were also examined. Compounds 22 and 23 showed antiviral activities against HSV-1 and HSV-2 without showing significant toxicity to the host cells (MRC-5 cells). Although almost all of the nucleosides showed anti-HIV-1 activities, they were also cytotoxic to the host cells (MT-4).

Takuma Sasaki

Papers

Purealidins B and C, new bromotyrosine alkaloids from the okinawan marine sponge psammaplysilla purea

Alteramide A, a new tetracyclic alkaloid from a bacterium Alteromonas sp. associated with the marine sponge Halichondria okadai

Ascididemin, a novel pentacyclic aromatic alkaloid with potent antileukemic activity from the Okinawan tunicate Didemnum sp.

Nucleosides and nucleotides. 158. 1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)-cytosine, 1-(3-C-ethynyl-beta-D-ribo-pentofuranosyl)uracil, and their nucleobase analogues as new potential multifunctional antitumor nucleosides with a broad spectrum of activity.

Nucleosides and nucleotides. 185. Synthesis and biological activities of 4'alpha-C-branched-chain sugar pyrimidine nucleosides.