162,186 research outputs found
[Report to Chief J. E. Curry, by an unknown author #1]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
[Report to Chief J. E. Curry, by an unknown author #2]
No full textReport to Chief J. E. Curry, by an unknown author. The report contains a list of officers who gave depositions to the United States Attorney
Regioselective Functionalization of Indoles using Directing Group Strategy : An Efficient Transition Metal Catalysis
Get PDFThe thesis entitled “Regioselective Functionalization of Indoles using Directing Group Strategy: An Efficient Transition Metal Catalysis” is divided into two sections. Section A, which is presented in three chapters, describes the regioselective alkenylation of indoles using directing group strategy. Whereas, Section B, which is divided in to two chapters, narrates the synthesis of 4-amino indoles using directing group strategy and site selective addition of maleimide to indole at C2-position.
Section A
Chapter 1. C2-Alkenylation of indoles
The indole ring system is one of the most abundant heterocycles present in nature. The synthesis and functionalization of indoles is one of the major areas of focus for synthetic organic chemists.1 Alkenylation of indole at C2-position is a challenging task due to the electrophilic nature of the reaction. For this reason, the functionalization of indole at C2-position is less addressed. In this chapter, a highly regioselective alkenylation of indole at the C2-position has been described by using the Ru(II) catalyst and employing a directing group (DG) strategy.2 This directing group strategy offers rare selectivity for the alkenylation of N-benzoylindole at the C2-position in the presence of the more reactive C3-position. A variety of N-benzoylindole derivatives are shown to undergo alkenylation at C2-positon. Deprotection of the benzoyl group has also been demonstrated, and the resulting products serve as a useful synthon for synthesizing a variety of natural products. A few representative examples are highlighted in Scheme 1.3
1 (a) Cacchi, S.; Fabrizi, G. Chem. Rev. 2005, 105, 2873.
(b) Karamyan, K. A. J.; Hamann, M. T. Chem. Rev. 2010, 110, 4489.
2 (a) Lyons, T. W.; Sanford, M. S. Chem. Rev. 2010, 110, 1147.
(b) Engle, K. M.; Mei, T.-S.; Wasa, M.; J.-Q. Yu, Acc. Chem. Res. 2012, 45, 788.
(c) Neufeldt, S. R.; Sanford, M. S. Acc. Chem. Res. 2012, 45, 936.
(d) Arockiam, P. B.; Bruneau, C.; Dixneuf, P. H. Chem. Rev. 2012, 112, 5879.
3 Lanke, V.; Prabhu, K. R. Org. Lett. 2013, 15, 2818.
Scheme 1: C2- Alkenylation of indoles
Chapter 2 describes a highly regioselective alkenylation of indoles at the C4-position by employing aldehyde functional group as a directing group, and Ru as a catalyst, under a mild reaction conditions. This approach leads to a short synthetic route for C4-alkenylated indoles, which serve as precursors for ergot alkaloids and related heterocyclic compounds.4 Further The potential of the present strategy has been demonstrated by performing (i) scale up reaction, (ii) selective reduction of olefin double bond and (iii) synthesizing substituted 1,3,4,5-tetrahydrobenzo[cd] in two steps with an overall yield of 68%. 1,3,4,5-Tetrahydrobenzo[cd] is one of the key intermediates for synthesizing ergot alkaloids. A few examples are highlighted in Scheme 2.5
4 (a) Horwell, D. C. Tetrahedron 1980, 36, 3123.
(b) Kozikowski, A. P.; Ishida, H. J. Am. Chem. Soc. 1980, 102, 4265.
(c) Oppolzer, W.; Grayson, J. I.; Wegmann, H.; Urrea, M. Tetrahedron 1983, 39, 3695.
(d) Hatanaka, N.; Ozaki, O.; Matsumoto, M. Tetrahedron Lett. 1986, 27, 3169.
(e) Horwell, D. C.; Verge, J. P. Phytochemistry 1979, 18, 519.
5 anke, V.; Prabhu, K. R. Org. Lett. 2013, 15, 6262.
Scheme 2: C4- Alkenylation of indoles
Chapter 3 of Section A, presents a novel mode of selective alkenylation of indoles using Ru and Rh catalyst. In these alkenylation reactions, selectivity between C2- and C4-positions of indole framework has been achieved by altering the property of directing group. Methyl ketone, as directing group, furnishes exclusively C2-alkenylated product, whereas trifluoromethyl ketone as a directing group changes the selectivity to C4, indicating that electronic nature of the directing group controls the choice between a 5-membered and 6-membered metallacycle. Developing such divergent and selective C-H functionalizations, between C2- and C4-positions, on the indole framework can lead to easy and short synthetic routes for natural, unnatural and biologically-active compounds.6 Further screening of other carbonyl derived directing groups revealed that strong and weak directing groups exhibit opposite selectivity. Experimental
6 (a) Bronner, S. M.; Goetz, A. E.; Garg, N. K. J. Am. Chem. Soc. 2011, 133, 3832.
(b) Nathel, N. F. F.; Shah, T. K.; Bronner, S. M.; Garg, N. K. Chem. Sci., 2014, 5, 2184.
(c) A Beilstein/Crossfire search shows that more than 600 C4- substituted indole-containing natural products exist and nearly 10,000 bioactive C4-substituted indoles have been reported. controls, deuteration experiments and preliminary DFT calculations lend support to the proposed mechanism. A few representative examples are highlighted in Scheme 3.7
Scheme 3: C4- vs C2-Alkenylation of ndoles
Deuterium Labeling studies were carried out to shed light on the site of metallacycle formation and hence the origin of selectivity. Both COCF3 and COCH3 substrates were independently subjected to both standard conditions A and B, along with either D2O or AcOD as deuterium sources (Scheme 4).
7 Lanke, V.; Bettadapur, K. R.; Prabhu, K. R. Manuscript submitted.
Scheme 4: Deuterium labeling studies
The Section B is divided into 2 chapters.
Chapter 1 presents a method for synthesizing of 3-(indol-2-yl) succinimide derivatives by using a directing group strategy. Selective functionalization at C2-position of indole in the presence of highly reactive C3-position has been achieved. A conjugate addition, instead of Heck-type reaction, has been achieved by careful selection of the alkene partner (maleimides and maleate esters). This selectivity has been achieved by avoiding β-hydride elimination. Succinimide derivatives are structural motifs that are found in many natural products and drug molecules. Moreover, succinimides can be easily reduced into 5-membered pyrrolidine rings, γ-lactams and lactims, which are part of structural scaffolds of useful natural products.8 Further the application of the protocol has been showcased by performing reduction to obtain pyrrolidine and 1,4 diols. A few representative examples are highlighted in Scheme5.9 8 (a)Crider, A. M.; Kolczynski, T. M.; Yates, K. M. J. Med. Chem. 1980, 23, 324.
(b) Isaka, M.; Rugseree, N.; Maithip, P.; Kongsaeree, P.; Prabpai, S.; Thebtaranonth, Y. Tetrahedron 2005, 61, 5577.
(c) Uddin, J.; Ueda, K.; Siwu, E. R. O.; Kita, M.; Uemura, D. Bioorg. Med. Chem. 2006, 14, 6954. (d) Hubert, J. C.; Wijnberg, J. B. P. A.; Speckamp, W. N. Tetrahedron 1975, 31, 1437.
(e) Wijnberg, J. B. P. A.; Schoemaker, H. E.; Speckamp, W. N. Tetrahedron 1978, 34, 179.
9 Lanke, V.; Bettadapur, K. R.; Prabhu, K. R. Org. Lett. 2015, 17, 4662.
Scheme 5: Addition of Maleimide to Indole at C2-position
Chapter 2 describes a highly regioselective amidation of unprotected indoles at the C4-position by employing aldehyde functional group as a directing group. This reaction has been performed using Ir(III) catalyst, under mild reaction conditions. Thus, an efficient, simple, short synthetic route for C4-amido indoles has been achieved. C4-Amido indoles are privileged molecules, which serve as precursors for indolactum V,10 teleocidin and related heterocyclic compounds.11 To the best our knowledge, this is the first report of using aldehyde as a directing group for amidation reactions. The potential of the present strategy has been demonstrated by performing scaling up reaction, and deprotection of tosyl group to obtain corresponding amines. A few representative examples are highlighted in Scheme 6.12
10 Garg, N. K. et al., J. Am. Chem. Soc. 2011, 133, 3832
11 Kehler, J. J. Med. Chem. 2014, 57, 5823
12 Lanke, V.; Prabhu, K. R. (Manuscript submitted).
Scheme 6: C4- amidation of indoles
Sports camp with six months of support from a local sports club as a treatment for childhood obesity.
No full textAIMS: Although childhood obesity is becoming increasingly prevalent, treatment options are limited and the continued development of effective treatment strategies is necessary. It is equally important to explore involvement of other resources in society, such as sports associations. This study was designed to investigate the possibility of reducing the degree of obesity in obese children by focusing on physical activity as an intervention.
METHODS: Seventy-six children (40 boys) aged 8-12 years (mean age 10.5 years, mean body mass index (BMI) 28.9, standard deviation (SD) 3.0; mean BMI z-score 3.24, SD 0.49) were invited to participate in a one-week sports camp and six-month support system. After the camp a sports coach from a local sports club supported the child during participation in a chosen sport for six months. Weight, height, body composition (using dual energy x-ray absorptiometry and magnetic resonance imaging), and lifestyle (using a questionnaire) were measured at baseline and after 12 months. Data were pooled from two camps, one with a self-selected control group and one randomized controlled trial.
RESULTS: Twelve months after the camp the intervention group had a significant decrease in BMI z-score (baseline BMI z-score 3.22; follow up 3.10, p = 0.023). The control group also reduced their BMI z-score (baseline BMI z-score 3.27; follow up 3.18, p = 0.022). No differences were found in baseline values, follow-up values, or changes in BMI z-score between groups, nor between boys and girls.
CONCLUSIONS: The focus on physical activity as an intervention had no effect on degree of obesity when compared with a waiting list control group
Murder on the mountain: author talk with Peter J. Wosh
No full textAuthor talk by Peter J. Wosh on May 5th, 2022, on his book, "Murder on the Mountain: crime, passion, and punishment in gilded age New Jersey.
Mr. Melvin J. Collier, RWWL AUC, June 2011
No full textThis video is a conversation with Mr. Melvin J. Collier. Mr. Collier talks about his book, "From Mississippi to Africa: A Journey of Discovery". Daniel Le, AUC Woodruff Library, is the interviewer
A Tripartite Post-Recession Rebalancing
No full textIn this latest Advance & Rutgers Report, entitled “A Tripartite Post-Recession Rebalancing,” Dean James W. Hughes and Professor Joseph J. Seneca deliver an incisive assessment of the current market conditions and obstacles in the path of our economic recovery. They offer a statistical cautionary tale that the private and public sector need to hear and acknowledge in order for the economy to make continued progress.This report was published as Issue Paper Number 7, November 2011, in Advance & Rutgers Report
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
Get PDFFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
Get PDFAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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