Joanne E. Harvey
Other affiliations: University of York, Victoria University, Australia, Industrial Research Limited ...read more
Bio: Joanne E. Harvey is an academic researcher from Victoria University of Wellington. The author has contributed to research in topics: Cyclopropane & Ring (chemistry). The author has an hindex of 15, co-authored 62 publications receiving 630 citations. Previous affiliations of Joanne E. Harvey include University of York & Victoria University, Australia.
Papers published on a yearly basis
TL;DR: A novel combination of ring-closing metathesis (RCM) and Ramberg-Bäcklund reactions enables the C1'-C2' alkene to be masked as a sulfone during formation of the macrocycle by ring closing meetingathesis at the C7'-C8' olefin, thus avoiding competing formation of a cyclohexene.
Abstract: The bioactive resorcylic acid lactone aigialomycin D (1) has been synthesized by a novel combination of ring-closing metathesis (RCM) and Ramberg−Backlund reactions. This synthetic strategy enables the C1′−C2′ alkene to be masked as a sulfone during formation of the macrocycle by ring closing metathesis at the C7′−C8′ olefin, thus avoiding competing formation of a cyclohexene. A subsequent Ramberg−Backlund reaction efficiently produces the C1′−C2′ E-alkene. This combined RCM/Ramberg−Backlund reaction strategy should be widely applicable to the synthesis of macrocyclic dienes.
TL;DR: The conversion of cyclopropane-fused carbohydrates into oxepines is an attractive method for accessing diverse members of the septanoside family of carbohydrate mimetics, and 2-Bromooxepines are obtained through silver(I)-promoted thermal ring expansion of a d-glucal-derived gem-dihalocyclopropanated sugar.
Abstract: The conversion of cyclopropane-fused carbohydrates into oxepines is an attractive method for accessing diverse members of the septanoside family of carbohydrate mimetics. 2-Bromooxepines are obtained through silver(I)-promoted thermal ring expansion of a d-glucal-derived gem-dihalocyclopropanated sugar. In contrast, cyclopropane ring cleavage under basic conditions leads to 2-C-branched pyranosides, not the 2-bromooxepine structures assigned in an earlier report.
TL;DR: In this paper, homochiral, highly functionalised organolithium reagents derived from l -serine have been generated and reacted with electrophiles, and the novel enantiomerically pure adducts thus obtained were then converted, through β-amino alcohols, into novel non-proteinogenic αamino acids.
Abstract: Homochiral, highly functionalised organolithium reagents derived from l -serine have been generated and reacted with electrophiles. The novel enantiomerically pure adducts thus obtained were then converted, through β-amino alcohols, into novel non-proteinogenic α-amino acids. The methodology also made available a novel boronic acid which was then employed as a Suzuki cross-coupling partner, elaborating a new pathway to phenylalanine analogues.
TL;DR: A regioselective palladium-catalyzed allylic alkylation cascade forms furo[3,2-c]pyrans from various cyclic β-dicarbonyl bis-nucleophiles and 3,6-dihydro-2H-pyran bis-electrophiles by combination of allylic carbonate and anomeric siloxy leaving groups in the dihydropyran substrate.
Abstract: A regioselective palladium-catalyzed allylic alkylation cascade forms furo[3,2-c]pyrans from various cyclic β-dicarbonyl bis-nucleophiles and 3,6-dihydro-2H-pyran bis-electrophiles. The combination of allylic carbonate and anomeric siloxy leaving groups in the dihydropyran substrate allows control of the many regiochemical possibilities in this reaction. Annulation proceeds stereoconvergently to give cis-fused furopyrans from either cis- or trans-substituted starting material.
TL;DR: This coherent review will contribute towards the better understanding of the correlation of chemical processes, stability profile and biological activity; therefore, it will help to design the shelf-life stable formulations containing AVMs.
Abstract: Naturally occurring avermectins (AVMs) and its derivatives are potent endectocide compounds, well-known for their novel mode of action against a broad range of nematode and anthropod animal parasites. In this review, chemical and pharmaceutical aspects of AVM derivatives are described including stability, synthetic and purification processes, impurities and degradation pathways, and subsequent suggestions are made to improve the chemical stability. It has been found out that unique structure of AVM molecules and presence of labile groups facilitated the derivatization of AVM into various compounds showing strong anthelmintic activity. However, the same unique structure is also responsible for labile nature related to sensitive stability profile of molecules. AVMs are found to be unstable in acidic and alkaline conditions. In addition, these compounds are sensitive to strong light, and subsequently presence of photo-isomer in animals treated topically with AVM product is well known. The pharmacoepial recommendations for addition of antioxidant into drug substance, as well as its products, arises from the fact that AVM are very sensitive to oxidation. Formations of solvates, salts, epoxides, reduction of double bonds and developing liquid formulation around pH 6.2, were some chemical approaches used to retard the degradation in AVM. This coherent review will contribute towards the better understanding of the correlation of chemical processes, stability profile and biological activity; therefore, it will help to design the shelf-life stable formulations containing AVMs.
29 Apr 2010
TL;DR: Physical vapor deposition (PVD) process technology from the characterizing and preparing the substrate material, through deposition processing and film characterization, to post-deposition processing is discussed in this paper.
Abstract: This updated version of the popular handbook further explains all aspects of physical vapor deposition (PVD) process technology from the characterizing and preparing the substrate material, through deposition processing and film characterization, to post-deposition processing. The emphasis of the new edition remains on the aspects of the process flow that are critical to economical deposition of films that can meet the required performance specifications, with additional information to support the original material. The book covers subjects seldom treated in the literature: substrate characterization, adhesion, cleaning and the processing. The book also covers the widely discussed subjects of vacuum technology and the fundamentals of individual deposition processes. However, the author uniquely relates these topics to the practical issues that arise in PVD processing, such as contamination control and film growth effects, which are also rarely discussed in the literature. In bringing these subjects together in one book, the reader can understand the interrelationship between various aspects of the film deposition processing and the resulting film properties. The author draws upon his long experience with developing PVD processes and troubleshooting the processes in the manufacturing environment, to provide useful hints for not only avoiding problems, but also for solving problems when they arise. He uses actual experiences, called 'war stories', to emphasize certain points. Special formatting of the text allows a reader who is already knowledgeable in the subject to scan through a section and find discussions that are of particular interest. The author has tried to make the subject index as useful as possible so that the reader can rapidly go to sections of particular interest. Extensive references allow the reader to pursue subjects in greater detail if desired. The book is intended to be both an introduction for those who are new to the field and a valuable resource to those already in the field. The discussion of transferring technology between R&D and manufacturing provided in Appendix 1, will be of special interest to the manager or engineer responsible for moving a PVD product and process from R&D into production. Appendix 2 has an extensive listing of periodical publications and professional societies that relate to PVD processing. The extensive Glossary of Terms and Acronyms provided in Appendix 3 will be of particular use to students and to those not fully conversant with the terminology of PVD processing or with the English language. This title is fully revised and updated to include the latest developments in PVD process technology. It includes 'War stories' drawn from the author's extensive experience emphasize important points in development and manufacturing. Appendices include listings of periodicals and professional societies, terms and acronyms, and material on transferring technology between R&D and manufacturing.
TL;DR: Each class of drugs used in treatment is discussed, along with their mechanism of action, in vitro and clinical efficacy, and side effects and contraindications, and Recommendations are made for the preferred treatment in different clinical situations.
Abstract: Giardia lamblia is both the most common intestinal parasite in the United States and a frequent cause of diarrheal illness throughout the world. In spite of its recognition as an important human pathogen, there have been relatively few agents used in therapy. This paper discusses each class of drugs used in treatment, along with their mechanism of action, in vitro and clinical efficacy, and side effects and contraindications. Recommendations are made for the preferred treatment in different clinical situations. The greatest clinical experience is with the nitroimidazole drugs, i.e., metronidazole, tinidazole, and ornidazole, which are highly effective. A 5- to 7-day course of metronidazole can be expected to cure over 90% of individuals, and a single dose of tinidazole or ornidazole will cure a similar number. Quinacrine, which is no longer produced in the United States, has excellent efficacy but may be poorly tolerated, especially in children. Furazolidone is an effective alternative but must be administered four times a day for 7 to 10 days. Paromomycin may be used during early pregnancy, because it is not systematically absorbed, but it is not always effective. Patients who have resistant infection can usually be cured by a prolonged course of treatment with a combination of a nitroimidazole with quinacrine.
TL;DR: Mechanistically, C-glycosylation reactions can involve glycosyl electrophilic/cationic species, anionic species, radical species, or transition-metal complexes, which are discussed as subcategories under each type of sugar precursor.
Abstract: Advances in the chemical synthesis of C-pyranosides/furanosides are summarized, covering the literature from 2000 to 2016. The majority of the methods take advantage of the construction of the glycosidic C—C bond. These C-glycosylation methods are categorized herein in terms of the glycosyl donor precursors, which are commonly used in O-glycoside synthesis and are easily accessible to nonspecialists. They include glycosyl halides, glycals, sugar acetates, sugar lactols, sugar lactones, 1,2-anhydro sugars, thioglycosides/sulfoxides/sulfones, selenoglycosides/telluroglycosides, methyl glycosides, and glycosyl imidates/phosphates. Mechanistically, C-glycosylation reactions can involve glycosyl electrophilic/cationic species, anionic species, radical species, or transition-metal complexes, which are discussed as subcategories under each type of sugar precursor. Moreover, intramolecular rearrangements, such as the Claisen rearrangement, Ramberg–Backlund rearrangement, and 1,2-Wittig rearrangement, which usuall...
TL;DR: In this paper, the Suzuki-Miyaura cross-couplings of organoboronic acids or organotrifluoroborates with aryl and alkenyl halides or triflates have become classic methods for generating carbon-carbon bonds.
Abstract: Palladium-catalysed Suzuki–Miyaura cross-couplings of organoboronic acids or organotrifluoroborates with aryl and alkenyl halides or triflates have become classic methods for generating carbon–carbon bonds. For this reaction, not only sp2-hybridized but also sp3-hybridized organoboron derivatives can be employed. However, alkylboronic acids or trifluoroborates are generally less reactive than arylboron derivatives. The coupling of primary alkylboronic acids or alkyltrifluoroborates with aryl or alkenyl halides is well known, and the reaction gives the coupling products with high selectivities, relatively high turnover numbers and in good yields with several catalysts. On the other hand, secondary alkylboronic acids or trifluoroborates, except for cyclopropylboron derivatives, are much less reactive, and very few catalyst are able to activate such compounds. Because of the hybridization of cyclopropanes, which confers significant aromatic character, several reactions have successfully been performed with cyclopropylboronic acids or trifluoroborates. The stereochemistries of substituted cyclopropylboron derivatives were maintained in the course of the reactions. For all these couplings with primary or secondary alkylboron derivatives, aryl iodides, bromides, chlorides or triflates and alkenyl iodides, bromides or triflates were employed. Alkenyl chlorides have attracted less attention. The reactions with alkenyl halides are stereoselective. A few examples of couplings between sp3-hybridized organoboronic acids and alkyl halides have also been reported.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)