24,303 research outputs found
From lithium ketazides to isomeric silylketazine-rings - imine-enamine tautomerism
No full textDi(tert-butylmethyl)ketazine (I) reacts with n-BuLi in a 1: 1 molar ratio to give a monolithium salt (II). The reaction of 11 with 'Bu2SiF2 in n-hexane leads, even in a 1:1 molar ratio, to the formation of the isomeric five- and four-membered ring compounds I and 2. Compound 1 has an endocyclic imine and an exocyclic enamine unit. The opposite is found for 2. The acyclic mono substitution product, 'Bu2SiFCH2-C'Bu=N-N=C'BuCH3 (III) could not be isolated. It reacts with the lithium ketazide to give 1 or 2. 1 is reformed. The reaction in THF yields only the four-membered ring 2. In a comparable reaction of the lithium ketazide and (H3C)(2)SiF2, the substitution product 3 could be isolated. A possible formation mechanism for 2 includes an intermediate silene IV. Both compounds 1 and 2 react with H3C-OH under cleavage of the endocyclic Si-N-bond to give the addition product 5. The reaction mechanism includes a hydrogen shift from a nitrogen atom to a carbon atom via an imine-enamine tautomerism. In a 2:1 molar ratio, n-BuLi and the di(tert-butylmethyl)-ketazine (I) form the dilithium salt, 6. Compound 6 crystallizes from THF as trimer with four imine and two enamine units. A seven-membered ring (7) isomeric to 1 and 2 is the result of the reaction of 6 with 'Bu2SiF2. Compound 7 contains one imine and one enamine unit in the ring skeleton. The comparable reaction of the (CH3)(3)Si-substituted dilithium-di(tert-butylmethyl)ketazide and 'Bu2SiF2 yields the five-membered ring compound 8 with one endocyclic imine and one exocyclic enamine unit. Quantum chemical calculations of 1, 2, 7 and the intermediate silene IV have been carried out and show a low energy difference between the cyclic silyl-ketazine isomers. (C) 2007 Elsevier B.V. All rights reserved
Synthesis and Cyclisation of Boryl- and Silylhydrazones
No full textReactions of the lithium salts of the tert-butylmethylhydrazones Me(3)C(Me)C=N-NLiR, (R = H, Me, CMe(3)) with fluorosilanes and -boranes in a molar ratio 1: 1 gave the silyl- (1-3, 5, 6) and borylhydrazones (4, 8) Me(3)C(Me)C=N-N(R)R'; 1: R = H. R' = SiFMe(2); 2: R = H, R' = SiMe(2)CMe(3); 3: R = H, R' = SiF(CMe(3))(2); 4: R = H, R' = BFN(SiMe(3))(2); 5: R = Me(3)C, R' = SiF(2)CMe(3); 6: R = Me(3)C, R' = F(2)SiC(SiMe(3))(3); 8: R = Me(3)C, R' = BFN(SiMe(3))(2). The lithiated hydrazone Me(2)C=N-NH(Me) reacted with F(3)SiC(SiMe(3))(3) to give the silylhydrazone Me(2)C=N- NHSiF(2)C(SiMe(3))(3), 7. Because of the fluoro functionality of 1 and 4, the bis-hydrazonylsilane 9 and the bis- and tris-hydrazonylboranes 10 and 11 could be synthesised, (Me(3)C(Me)C=N-NH)(2)R; 9: R = SiMe(2), 10: R = BN(SiMe(3))(2); 11: (Me(3)C(Me)C=N-NH)(3)B. Starting from 2 and its lithium salt, secondary substitutions are possible. Bis(silyl)- and silyl(boryl)hydrazones are formed (12-15): Me(3)C(Me)C=N(R) (SiMe(2)CMe(3)) 12: R = SiFMe(2); 13: R = SiF(CMe(3))(2); 14: R = SiF1CMe3: 15: R = BFN(SiMe3)2. Ring closure occurs in the reaction of dilithiated Me2C=N NHCMe(3) with F(2)Si(CHMe(2))(2). The 1,2-diaza-3-sila-5-cyclopentene 16 is isolated. The fluorofunctional silyl-hydrazones 7, 12, and 13 cyclise in reactions with t-BuLi to give 1,2-diaza-3-sila-5-cyclopentenes 17-20; RN(N=CR' CH(2))R"; 17: R = Me, R' = Me(3)C, R" = SiFC(SiMe(3))(2); 18: R = Me(3)C, R' = SiMe(2)CMe(3), R" = SiMe(2); 19: R = Me(3)C, R' = SiMe(2)CMe(3), R" = Si(CMe(3))(2). A 1,2-diaza-3-bora-5-cyclopentene 20 is the result of the reaction of 8 with t-BuLi: Me(3)CN(N=CCMe(3)-CH(2))BN(SiMe(3))(2). The H-acidic methylene group of the five-membered ring in 20 can be lithiated with n-BuLi and substituted with fluorosilanes. Starting from 16 and 20, the silyl-substituted rings Me(3)CN(N=CMe-CHR)Si(CHMe(2))(2) 21-23 and 25 are obtained; 21: R = SiMe(3); 22: R = SiF(2)C(SiMe(3))(3); 23: R = SiF(3); 25: Me(3)CN[N=CC(Me)(3)CHSiMe(3)]BN(SiMe(3))(2). Using SiF(4) as fluorosilane, the main product is the difluorosilane containing two rings; F(2)Si[CHC(Me)=N-NCMe(3)- Si(CHMe(2))(2)](2). The methine group in 4-position of the silyl-substituted rings is also acidic and reacts with n-BuLi to give lithium salts which react with aminodifluoroboranes giving the ring compounds Me(3)CN[N=C(CMe(3))C(SiMe(2)R)(FBNR'SiMe(3))]SiMe(2) 26-28; 26: R = Me, R' = CMe(3); 27: R = F, R' = CMe(3); 28: R = F, R' = SiMe(3). In contrast to the substitution reactions of fluorosilanes with lithiated rings, an unusual oxidation reaction occurs starting from lithiated Me(3)CN(N=C(CMe(3))CH(2))Si(CHMe(2))(2) and ClSiMe(2)CMe(3) to give 29, in which a C-C bond in 4-position links wo five-membered lines. The disilane (Me(3)CSiMe(2))(2) is formed as a by-product of this reaction. The combination of the N-SiF(2)CMe(3)-substituted hydrazones 5 and 14 with t-BuLi in a molar ratio 1 :2 leads to the colourless, crystalline tricyclic products 30 and 31 which are dimeric 1,2-diaza-3-sila-3,5-cyclopentadienes. The molecular structures of 3, 6, 11, 30, and 31 are reported
Synthesis and Cyclisation of Boryl- and Silylhydrazones
No full textReactions of the lithium salts of the tert-butylmethylhydrazones Me(3)C(Me)C=N-NLiR, (R = H, Me, CMe(3)) with fluorosilanes and -boranes in a molar ratio 1: 1 gave the silyl- (1-3, 5, 6) and borylhydrazones (4, 8) Me(3)C(Me)C=N-N(R)R'; 1: R = H. R' = SiFMe(2); 2: R = H, R' = SiMe(2)CMe(3); 3: R = H, R' = SiF(CMe(3))(2); 4: R = H, R' = BFN(SiMe(3))(2); 5: R = Me(3)C, R' = SiF(2)CMe(3); 6: R = Me(3)C, R' = F(2)SiC(SiMe(3))(3); 8: R = Me(3)C, R' = BFN(SiMe(3))(2). The lithiated hydrazone Me(2)C=N-NH(Me) reacted with F(3)SiC(SiMe(3))(3) to give the silylhydrazone Me(2)C=N- NHSiF(2)C(SiMe(3))(3), 7. Because of the fluoro functionality of 1 and 4, the bis-hydrazonylsilane 9 and the bis- and tris-hydrazonylboranes 10 and 11 could be synthesised, (Me(3)C(Me)C=N-NH)(2)R; 9: R = SiMe(2), 10: R = BN(SiMe(3))(2); 11: (Me(3)C(Me)C=N-NH)(3)B. Starting from 2 and its lithium salt, secondary substitutions are possible. Bis(silyl)- and silyl(boryl)hydrazones are formed (12-15): Me(3)C(Me)C=N(R) (SiMe(2)CMe(3)) 12: R = SiFMe(2); 13: R = SiF(CMe(3))(2); 14: R = SiF1CMe3: 15: R = BFN(SiMe3)2. Ring closure occurs in the reaction of dilithiated Me2C=N NHCMe(3) with F(2)Si(CHMe(2))(2). The 1,2-diaza-3-sila-5-cyclopentene 16 is isolated. The fluorofunctional silyl-hydrazones 7, 12, and 13 cyclise in reactions with t-BuLi to give 1,2-diaza-3-sila-5-cyclopentenes 17-20; RN(N=CR' CH(2))R"; 17: R = Me, R' = Me(3)C, R" = SiFC(SiMe(3))(2); 18: R = Me(3)C, R' = SiMe(2)CMe(3), R" = SiMe(2); 19: R = Me(3)C, R' = SiMe(2)CMe(3), R" = Si(CMe(3))(2). A 1,2-diaza-3-bora-5-cyclopentene 20 is the result of the reaction of 8 with t-BuLi: Me(3)CN(N=CCMe(3)-CH(2))BN(SiMe(3))(2). The H-acidic methylene group of the five-membered ring in 20 can be lithiated with n-BuLi and substituted with fluorosilanes. Starting from 16 and 20, the silyl-substituted rings Me(3)CN(N=CMe-CHR)Si(CHMe(2))(2) 21-23 and 25 are obtained; 21: R = SiMe(3); 22: R = SiF(2)C(SiMe(3))(3); 23: R = SiF(3); 25: Me(3)CN[N=CC(Me)(3)CHSiMe(3)]BN(SiMe(3))(2). Using SiF(4) as fluorosilane, the main product is the difluorosilane containing two rings; F(2)Si[CHC(Me)=N-NCMe(3)- Si(CHMe(2))(2)](2). The methine group in 4-position of the silyl-substituted rings is also acidic and reacts with n-BuLi to give lithium salts which react with aminodifluoroboranes giving the ring compounds Me(3)CN[N=C(CMe(3))C(SiMe(2)R)(FBNR'SiMe(3))]SiMe(2) 26-28; 26: R = Me, R' = CMe(3); 27: R = F, R' = CMe(3); 28: R = F, R' = SiMe(3). In contrast to the substitution reactions of fluorosilanes with lithiated rings, an unusual oxidation reaction occurs starting from lithiated Me(3)CN(N=C(CMe(3))CH(2))Si(CHMe(2))(2) and ClSiMe(2)CMe(3) to give 29, in which a C-C bond in 4-position links wo five-membered lines. The disilane (Me(3)CSiMe(2))(2) is formed as a by-product of this reaction. The combination of the N-SiF(2)CMe(3)-substituted hydrazones 5 and 14 with t-BuLi in a molar ratio 1 :2 leads to the colourless, crystalline tricyclic products 30 and 31 which are dimeric 1,2-diaza-3-sila-3,5-cyclopentadienes. The molecular structures of 3, 6, 11, 30, and 31 are reported
Jack Alive / Martin Dead : The Location of the "Author" in Jack London\u27s Martin Eden
No full textThis essay is an attempt to read Martin Eden, Jack Londonʼs autobiographical novel, in terms of the inextricable relationship between the author and the protagonist. Critics have often taken the unbalanced plot and the lack of ironic distance between narrator and character in Martin Eden as the technical weakness of London, but this paper argues that the achievement of this novel owes a great deal to the attachment of London to Martin. The unbalanced structure is a necessary product of the severe struggle of the author to kill his romantic alter ego. // Martin, who aspires to win Ruth Morse, tries to cross class boundaries by making a career of a writer. Even after realizing the emptiness of Ruth, who turns out to be nothing but a typical figure of the bourgeoisie, he somehow persists in loving her. The notion underlying here is that, for Martin, love, career and art are fundamentally inseparable. He objects to the aestheteʼs view of Brissenden on account of his separation of art from career. Martinʼs identity and life consist only in the triunity of love/career/art; the alternative is the repudiation of life. Thus, the unnatural delay of his disappointment in love can be regarded as Londonʼs strategy to set the suicide of Martin as the necessary consequence of the story. // By finishing the story and killing Martin, London finally detaches himself from Martin, reconstructs his self, and, unlike Martin, survives as a professional writer. In this sense, Martin Eden is a story about “writerʼs self-reconstruction.
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Letter from Martin Chizzick
No full textCongratulations to Duane Pearsall for receiving the Enterpreneur of the Year award; note on the letter was written by Pearsall and it mentions that Martin, the author of the letter, died in a airplane accident
Robert Martin Tiffin's Mystery Man Newspaper Articles
No full textAdvertiser-Tribune newspaper clippings featuring a story about Robert Martin (written by Nancy Kleinhenz), a local author from Tiffin (Ohio) who wrote under the pseudonym of Lee Roberts, and two of his short stories. Martin wrote mystery novels in his spare time, creating more than 22 mystery novels. For more information about Robert Martin and a list of books go to http://www.mysteryfile.com/RMartin/JBennett.html
Experiences Using Large Scale Video Walls for Distance Education
No full textWe describe our experiences building and using the Rutgers Videowall, a low-cost telepresence system that has been used teaching 15 courses and colloquia. By relaxing typical spatial telepresence features, such as background continuity, we greatly reduced costs and gained flexibility in the rooms it could be deployed in. The lower costs and room flexibility enabled academic departments to use the wall, in contrast to traditional telepresence systems which remained inaccessible. We found that the Videowall’s spatial distortions did not have a significant impact on useability, as our initial survey results show that students had an overall positive experience.Technical report DCS-tr-72
Hans Martin Schwarz Collection 1934 - 1938
No full textThis collection contains clippings of articles by Hans Martin Schwarz (1917, Hamburg – 2006, New York, better known as Martin Ebon), published between 1934 and 1938 in German-Jewish newspapers on a wide variety of subjects such as sports, emigration, the political situation in Germany, and religious attitudes of the young. It also contains reviews of his books "Einer wie Du und Ich" and "Heiteres, Besinnliches, Nachdenkliches."digitizedHans Martin Schwarz (1917, Hamburg – 2006, New York, better known as Martin Ebon), was a journalist and author. In Germany during the 1930s, he published in a variety of German-Jewish periodicals, primarily the Israelitisches Familienblatt. After immigrating to the United States in 1938, he changed his name to Martin Ebon, and published dozens of books in the areas of world affairs and parapsychology.Processe
Interview with Father James Martin
No full textIn May 2011, the Ignatian Faculty Scholars at Regis University conducted a Skype interview with Father James Martin, S. J., author of The Jesuit Guide to Almost Everything. The Scholars had used Father Martin’s book as a text for their year of study, which focused on Ignatian Spirituality, the Ignatian Pedagogical Paradigm, and teaching and learning at a Jesuit university. The interview was transcribed and is printed below. Father Martin reflects on the book, and responds to questions about the book itself, about finding God in all learners, and about the Church
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