832 research outputs found

    NSM-based Cultural Dictionaries: For Language Learners and Beyond

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    For language learners, the transition from classroom to immersion is an exhausting and difficult one. Not least because of how language is used differently “in the real world” to how it is taught in classrooms. There are many “insider” dictionaries of language but few dictionaries which take a closer look at the important words and explain them in ways that learners can understand. Natural semantic metalanguage (NSM)’s way of defining culturally important terms and combining them with cultural scripts gives us an opportunity to go beyond the standard realm of definitions and explore the possibilities of what I am calling “cultural dictionaries”. This paper will discuss the current opening in learner lexicography to include emic cultural information. It will then discuss how NSM can contribute to such lexicographical practice. Finally, drawing on the first NSM-based cultural dictionary project—the Australian Dictionary of Invisible Culture for Teachers—it provides reflections, advice, and recommendations for future cultural dictionary projects

    An NSM-based cultural dictionary of Australian English: from theory to practice

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    This thesis is a 'thesis by creative project' consisting of a cultural dictionary of Australian English, and an exegesis which details the theoretical basis and decisions made throughout the creative process of this project. The project aims to produce a resource for ESL teachers on teaching the invisible culture of Australian English to migrants, using the Natural Semantic Metalanguage (NSM) (e.g. Wierzbicka, 2006) as a theoretical and methodological basis. The resource takes the form of an encyclopaedic dictionary focussing on Australian values, attitudes, and interactional norms, in response to the need for education resources describing the cultural ethos embodied in Australian English (Sadow, 2014). Best practice for teaching intercultural communicative competence and related skills is to use a method for teaching which encourages students to reflect on their experience and analyse it from an insider perspective (Tomlinson and Masuhara, 2013). This thesis takes the position and demonstrates that an NSM-based descriptive method can meet these practical requirements by providing a framework for describing both cultural semantics and cultural scripts. In response to teacher needs for a pedagogical tool, I created Standard Translatable English (STE) - a derivative of NSM specifically designed for language pedagogy. The exegesis part of this project, therefore, reports on the development of STE and the process, rationale, and results of creating a cultural dictionary using STE as a descriptive method. I also discuss the theoretical grounding of teaching invisible culture, the best-practice requirements for creating teaching materials and dictionaries, my methods for conducting user needs research, and the results, and the ultimate design choices which have resulted in a finished product, including supplementary materials to ensure that teachers are well prepared to use an NSM-based approach in pedagogical contexts. The main body of this project, however, is the cultural dictionary - The Australian Dictionary of Invisible Culture for Teachers - comprising approximately 300 entries which describes, in STE, essential aspects of the values, attitudes, interactional norms, cultural keywords, and culture-specific language of Anglo-Australian English. The cultural dictionary is formatted as an eBook to enhance accessibility and practicality for teachers in classroom contexts. Drawing on previous dictionaries and on lexicography, the entries include a range of lexicographical information such as examples, part-of-speech, and cross-referencing. This innovative cultural dictionary represents the first targeted work into the applications of NSM and NSM-derived frameworks. It is the first dictionary of invisible culture in Australian English in this framework, and the only current resource which is aimed at maximum translatability for the English language education context

    Concerted C−N and C−H Bond Formation in a Magnesium-Catalyzed Hydroamination

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    Coordinatively saturated ToMMgMe (1; ToM = tris(4,4-dimethyl-2-oxazolinyl)phenylborate) is an active precatalyst for intramolecular hydroamination/cyclization at 50 °C. The empirical rate law of −d[substrate]/dt = kâ€Čobs[Mg]1[substrate]1 and Michaelis−Menten-type kinetics are consistent with a mechanism involving reversible catalyst−substrate association prior to cyclization. The resting state of the catalyst, ToMMgNHCH2CR2CH2CH═CH2 [R = Ph, Me, —(CH2)5—], is isolable, but isolated magnesium amidoalkene does not undergo unimolecular cyclization at 50 °C. However, addition of trace amounts of substrate allows cyclization to occur. Therefore, we propose a two-substrate, six-center transition state involving concerted C—N bond formation and N—H bond cleavage as the turnover-limiting step of the catalytic cycle

    The Synthesis and Characterization of New, Robust Titanium (IV) Scorpionate Complexes

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    Titanium complexes possessing sterically encumbered ligands have allowed for the preparation of reactive moieties (imido, alkylidene and alkylidyne species) relevant to reactions such as olefin polymerization and alkyne hydroamination. For this reason, we have targeted robust scorpionate ancillary ligands to support reactive titanium centers. Thus, a series of titanium complexes were synthesized using an achiral oxazoline-based scorpionate ligand, tris(4,4-dimethyl-2-oxazolinyl)phenyl borate [To^M^]^-^ as well as the related chiral ligand, tris(4-isopropyl-2-oxazolinyl)phenyl borate [To^P^]^-^. The complex [Ti(κ^3^- To^M^)Cl~3~] was prepared in moderate yield (43%) by the rapid (<1 min at room temperature) reaction of Li[To^M^] and TiCl~4~ in methylene chloride; this new compound was characterized by ^1^H NMR spectroscopy as the expected C~3v~-symmetric species. One route to Ti (IV) alkyls involves salt metathesis; accordingly, syntheses of [To^M^]Ti alkyl complexes by interaction of [Ti(κ^3^-To^M^)Cl~3~] and one or three equivalents of alkylating agents, such as benzyl potassium (KCH~2~C~6~H~5~), trimethylsilylmethyl
lithium (LiCH~2~Si(CH~3~) ~3~), or neopentyl lithium (LiCH~2~C(CH~3~)~3~) are currently under investigation. The complexes [Ti(=NBut) (κ~3~-To^M^)(Cl)(Bu^t^py)] (Bu^t^py=4 tert-butylpyridine) and [Ti(=NBu^t^) (κ~3~-To^P^)(Cl)(Bu^t^py)] were synthesized by reaction of the known Ti imido [Ti(=NBu^t^)(Cl)~2~(Bu^t^py)~2~] with Li[To^M^] or Li[To^P^], respectively, by stirring overnight in methylene chloride at ambient temperature. The complexes were identified using ^1^H NMR spectroscopy, ^1^H-^13^C HMQC and ^1^H-^15^N HMBC correlation experiments

    Magnesium-Catalyzed Mild Reduction of Tertiary and Secondary Amides to Amines

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    The first example of a catalytic hydroboration of amides for their deoxygenation to amines is reported. This transformation employs an earth-abundant magnesium-based catalyst. Tertiary and secondary amides are reduced to amines at room temperature in the presence of pinacolborane (HBpin) and catalytic amounts of ToMMgMe (ToM = tris(4,4-dimethyl-2-oxazolinyl)phenylborate). Catalyst initiation and speciation is complex in this system, as revealed by the effects of concentration and order of addition of the substrate and HBpin in the catalytic experiments. ToMMgH2Bpin, formed from ToMMgMe and HBpin, is ruled out as a possible catalytically relevant species by its reaction with N,N-dimethylbenzamide, which gives Me2NBpin and PhBpin through C–N and C–C bond cleavage pathways, respectively. In that reaction, the catalytic product benzyldimethylamine is formed in only low yield. Alternatively, the reaction of ToMMgMe and N,N-dimethylbenzamide slowly gives decomposition of ToMMgMe over 24 h, and this interaction is also ruled out as a catalytically relevant step. Together, these data suggest that catalytic activation of ToMMgMe requires both HBpin and amide, and ToMMgH2Bpin is not a catalytic intermediate. With information on catalyst activation in hand, tertiary amides are selectively reduced to amines in good yield when catalytic amounts of ToMMgMe are added to a mixture of amide and excess HBpin. In addition, secondary amides are reduced in the presence of 10 mol % ToMMgMe and 4 equiv of HBpin. Functional groups such as cyano, nitro, and azo remain intact under the mild reaction conditions. In addition, kinetic experiments and competition experiments indicate that B–H addition to amide C═O is fast, even faster than addition to ester C═O, and requires participation of the catalyst, whereas the turnover-limiting step of the catalyst is deoxygenation

    Mixed N‑Heterocyclic Carbene−Bis(oxazolinyl)borato Rhodium and Iridium Complexes in Photochemical and Thermal Oxidative Addition Reactions

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    In order to facilitate oxidative addition chemistry of fac-coordinated rhodium(I) and iridium(I) compounds, carbene–bis(oxazolinyl)phenylborate proligands have been synthesized and reacted with organometallic precursors. Two proligands, PhB(OxMe2)2(ImtBuH) (H[1]; OxMe2 = 4,4-dimethyl-2-oxazoline; ImtBuH = 1-tert-butylimidazole) and PhB(OxMe2)2(ImMesH) (H[2]; ImMesH = 1-mesitylimidazole), are deprotonated with potassium benzyl to generate K[1] and K[2], and these potassium compounds serve as reagents for the synthesis of a series of rhodium and iridium complexes. Cyclooctadiene and dicarbonyl compounds {PhB(OxMe2)2ImtBu}Rh(η4-C8H12) (3), {PhB(OxMe2)2ImMes}Rh(η4-C8H12) (4), {PhB(OxMe2)2ImMes}Rh(CO)2 (5), {PhB(OxMe2)2ImMes}Ir(η4-C8H12) (6), and {PhB(OxMe2)2ImMes}Ir(CO)2 (7) are synthesized along with ToMM(η4-C8H12) (M = Rh (8); M = Ir (9); ToM = tris(4,4-dimethyl-2-oxazolinyl)phenylborate). The spectroscopic and structural properties and reactivity of this series of compounds show electronic and steric effects of substituents on the imidazole (tert-butyl vs mesityl), effects of replacing an oxazoline in ToMwith a carbene donor, and the influence of the donor ligand (CO vs C8H12). The reactions of K[2] and [M(ÎŒ-Cl)(η2-C8H14)2]2 (M = Rh, Ir) provide {Îș4-PhB(OxMe2)2ImMesâ€ČCH2}Rh(ÎŒ-H)(ÎŒ-Cl)Rh(η2-C8H14)2 (10) and {PhB(OxMe2)2ImMes}IrH(η3-C8H13) (11). In the former compound, a spontaneous oxidative addition of a mesityl ortho-methyl to give a mixed-valent dirhodium species is observed, while the iridium compound forms a monometallic allyl hydride. Photochemical reactions of dicarbonyl compounds 5 and 7 result in C–H bond oxidative addition providing the compounds {Îș4-PhB(OxMe2)2ImMesâ€ČCH2}RhH(CO) (12) and {PhB(OxMe2)2ImMes}IrH(Ph)CO (13). In 12, oxidative addition results in cyclometalation of the mesityl ortho-methyl similar to 10, whereas the iridium compound reacts with the benzene solvent to give a rare crystallographically characterized cis-[Ir](H)(Ph) complex. Alternatively, the rhodium carbonyl 5 or iridium isocyanide {PhB(OxMe2)2ImMes}Ir(CO)CNtBu (15) reacts with PhSiH3 in the dark to form the silyl compound {PhB(OxMe2)2ImMes}RhH(SiH2Ph)CO (14) or {PhB(OxMe2)2ImMes}IrH(SiH2Ph)CNtBu (17). These examples demonstrate the enhanced thermal reactivity of {PhB(OxMe2)2ImMes}-supported iridium and rhodium carbonyl compounds in comparison to tris(oxazolinyl)borate, tris(pyrazolyl)borate, and cyclopentadienyl-supported compounds

    Reactions of Tris(oxazolinyl)phenylborato Rhodium(I) with C−X (X = Cl, Br, OTf) Bonds: Stereoselective Intermolecular Oxidative Addition

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    The achiral and enantiopure chiral compounds ToMRh(CO)2 (3) and ToPRh(CO)2 (4) (ToM = tris(4,4-dimethyl-2-oxazolinyl)phenylborate; ToP = tris(4S-isopropyl-2-oxazolinyl)phenylborate) were prepared to investigate stereoselective oxidative addition reactions and develop new catalytic enantioselective bond functionalization and cross-coupling chemistry. Reactivity at the rhodium center is first shown by the substitution of the carbonyl ligands in 3 and 4 in the presence of the appropriate ligand; thus treatment of ToMRh(CO)2 with P(OMe)3 provides ToMRh(CO)[P(OMe)3] (5). However, reaction of ToMRh(CO)2 and MeOTf (Tf = SO2CF3) affords the complex [{N-Me-Îș2-ToM}Rh(CO)2]OTf (6), resulting from N-oxazoline methylation rather than oxidative addition to rhodium(I). In contrast, ToMRh(CO)2 reacts with allyl bromide and chloroform, forming the rhodium(III) species (Îș3-ToM)Rh(η1-C3H5)Br(CO) (7) and (Îș3-ToM)Rh(CHCl2)Cl(CO) (8), respectively. Interestingly, the chiral ToPRh(CO)2 and CHCl3 react to give one diastereomer of (Îș3-ToP)Rh(CHCl2)Cl(CO) (9; 100:3 dr) almost exclusively. To evaluate the reactivity of these rhodium(I) compounds, the carbonyl stretching frequencies have been examined. The data for the mono- and trivalent rhodium oxazolinylborate compounds indicate that the electron-donating ability of [ToM]− is slightly greater than that of [ToP]−, and both ligands provide electronic environments that can be compared to the tris(pyrazolyl)borate ligand family

    Tris(oxazolinyl)boratomagnesium-Catalyzed Cross-Dehydrocoupling of Organosilanes with Amines, Hydrazine, and Ammonia

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    We report magnesium-catalyzed cross-dehydrocoupling of Si–H and N–H bonds to give Si–N bonds and H2. A number of silazanes are accessible using this method, as well as silylamines from NH3 and silylhydrazines from N2H4. Kinetic studies of the overall catalytic cycle and a stoichiometric Si–N bond-forming reaction suggest nucleophilic attack by a magnesium amide as the turnover-limiting step

    Synthesis of Monomeric Fe(II) and Ru(II) Complexes of Tetradentate Phosphines

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    rac-Bis[{(diphenylphosphino)ethyl}-phenylphosphino]methane (DPPEPM) reacts with iron(II) and ruthenium(II) halides to generate complexes with folded DPPEPM coordination. The paramagnetic, five-coordinate Fe(DPPEPM)Cl2 (1) in CD2Cl2 features a tridentate binding mode as established by 31P{1H} NMR spectroscopy. Crystal structure analysis of the analogous bromo complex, Fe(DPPEPM)Br2 (2) revealed a pseudo-octahedral, cis-α geometry at iron with DPPEPM coordinated in a tetradentate fashion. However, in CD2Cl2solution, the coordination of DPPEPM in 2 is similar to that of 1 in that one of the external phosphorus atoms is dissociated resulting in a mixture of three tridentate complexes. The chloro ruthenium complex cis-Ru(Îș4-DPPEPM)Cl2 (3) is obtained from rac-DPPEPM and either [RuCl2(COD)]2 [COD = 1,5-cyclooctadiene] or RuCl2(PPh3)4. The structure of 3 in both the solid state and in CD2Cl2 solution features a folded Îș4-DPPEPM. This binding mode was also observed in cis-[Fe(Îș4-DPPEPM)(CH3CN)2](CF3SO3)2 (4). Addition of an excess of CO to a methanolic solution of 1 results in the replacement of one of the chloride ions by CO to yieldcis-[Fe(Îș4-DPPEPM)Cl(CO)](Cl) (5). The same reaction in CH2Cl2 produces a mixture of 5and [Fe(Îș3-DPPEPM)Cl2(CO)] (6) in which one of the internal phosphines has been substituted by CO. Complexes 2, 3, 4, and 5 appear to be the first structurally characterized monometallic complexes of Îș4-DPPEPM
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