John A. Joule

Marine, nitrogen-containing heterocyclic naturalm products - structures and synthesis of compounds containing indole units

The structures, biological activities, and syntheses of marine natural products containing indole and dihydroindole nuclei are reviewed

Marine, Nitrogen-containing Heterocyclic Natural Products. Structures and Syntheses of Compounds Containing Quinoline and/or Isoqiunoline Units

The structures, biological activities, and syntheses of marine, natural products containing quinoline and/or isoquinoline nuclei are reviewed

Indole-β-nucleophilic substitution. Part 9 nitrogen nucleophiles. Syntheses of hydroxycryptolepine, cryptolepine, and quindoline

Abstract The alkaloids hydroxycryptolepine, cryptolepine and quindoline have been synthesised utilising the intramolecular β-nucleophilic substitution of a 1-phenylsulfonyl-2-acylindole.

Recent advances in the chemistry of 9H-carbazoles

Publisher Summary This chapter focuses on the chemistry of carbazoles. The reactions of the nucleus, introduction of substituents on carbazole nitrogen, reactions involving n-substituents, introduction of substituents onto carbazole carbon, and reactions involving c-substituents, outline the chemical properties of the carbazoles. The chapter also describes the methods for the synthesis of carbazoles. The method that has been most utilized for the preparation of aromatic carbazoles from noncarbazole precursors is the dehydrogenation of a tricyclic indole, usually a 1, 2, 3, 4-tetrahydrocarbazole. In addition, precursors such as biphenyls with an ortho nitrogen substituent, the diphenylamines, two separate six-membered ring components, and indoles are used for the synthesis of carbazoles.

The acid catalysed C3 epimerization of reserpine and deserpidine.

Abstract The epimerization at C3 of reserpine and deserpidine catalysed by acetic acid has been studied. 3-Deuterio-isoreserpine epimerizes without loss of label. Reserpine and isoreserpine methosalts do not epimerize at C3 in acetic acid. 3-Deuterio-isodeserpidine dedeuterates faster than it epimerizes. It is concluded that epimerization in these alkaloids involves initial C2 protonation according to Scheme II.

Synthesis of deoxyvariolin B

Abstract A synthesis of deoxyvariolin B ( 5 ) is described. The tricyclic pyridopyrrolopyrimidone ( 11 ) was prepared from 7-azaindole via lithiation at C-2, introduction of an aminoethyl side-chain, then closure of the third ring. A heteroaryl palladium(0)-catalysed coupling reaction was used to introduce a pyrimidine substituent at C-5.

4-(2,2-dimethyldioxalan-4-yl)-5-(quinoxalin-2-yl)-1,3-dithiol-2-one, a proligand relating to the cofactor of the oxomolybdoenzymes

Abstract The coupling of 2-iodoquinoxaline to 4-(2,2-dimethyl-1,3-dioxolan-4-yl)-5-(tri-n-butylstannyl)-1,3-dithiol-2-one5 gave 4-(2,2-dimethyl-1,3-dioxolan-4-yl)-5-(quinoxalin-2-yl)-1,3-dithiol-2-one 4.

1,3-dipolar cycloadditions to oxidopyraziniums

Abstract 1,5-Dimethyl-3-oxidopyrazinium (6) undergoes cycloadditions with methyl acrylate, acrylonitrile, diethyl maleate, maleimide, methyl propiolate and diethyl acetylenedicarboxylate.

Synthesis of Ascididemine and an Isomer

Ascididemine (9H-quino[4,3,2-de][1,10]phenanthrolin-9-one) (1) and an isomer (9H-quino[4,3,2-de][1,7]phenanthrolin-9-one) (4) have been synthesized starting from 1,4-dimethoxyacridone (7). The acridone was converted into 1,4-dimethoxy-9-ethynylacridine (11) by a triflate coupling. The ethynylacridine was converted in one-pot into 3H-6-methoxypyrido[2,3,4-kl]acridine (15) by reaction with sodium diformylamide; the mechanism of this key transformation is discussed. Conversion into 6H-4-bromopyrido[2,3,4-kl]acridin-6-one (19) and 6H-pyrido[2,3,4-kl]acridin-6-one (17), followed by reaction of each of these under high pressure conditions with acrolein N,N-dimethylhydrazone, gave ascididemine and its isomer, respectively.

Design and synthesis of acidic dipeptide hydroxamate inhibitors of procollagen C-proteinase

Procollagen C‐proteinase (PCP) is essential for the cleavage of procollagen to collagen in the extracellular matrix of animals and is, therefore, of major relevance to studies of ectopic deposition of collagen during fibrosis. In this study, we describe the design and synthesis of acidic side chain hydroxamate dipeptide inhibitors of PCP having IC50 values in the range 0.1–10 μm that mimic the location of aspartic acid residues in the P1′ and P2′ positions (i.e. immediately C‐terminal) of the PCP cleavage site in procollagen. Assays of PCP using purified human type I procollagen (a natural substrate of PCP) showed that the structure activity relationship of the inhibitors was improved with a glutamic acid mimic at the P1′ position. The results also showed that the presence of an acidic side chain at the P2′ position was not necessary for PCP inhibition. Marimastat and BB3103, which are highly effective inhibitors of matrix metalloproteinases and ADAMS proteinases, respectively, did not inhibit PCP. Copyright