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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 581-589 
    ISSN: 0009-2940
    Keywords: Silene, dichloroneopentyl- ; Imines ; Cycloaddition reactions ; 2-Silaazetidines ; Thermolysis reactions ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Silaheterocycles, XXIII[1]. - Synthesis and Thermolysis Reactions of Si-Functionalized 2-SilaazetidinesDichloroneopentylsilene (1) is formed in situ by the reaction of trichlorovinylsilane with LitBu. The [2 + 2] cycloaddition to imines yields Si, Si1-dichloro-functionalized 2-silaazetidines in a preparative scale. With aldimines as trapping agents for 1, the resulting SiN four-membered ring compounds are isolated as syn/anti1-isomers (e.g. syn/anti-15 and -16; syn/anti ≍ 2:1). Silene 1 is not liberated from the silaazetidines on heating, but the Si, Si1-dichloro-substituted silanimine Cl2Si=NtBu (24) is formed. This can be trapped by Me3SiOMe or Ph2C=NtBu to give the addition products 25 and 26, respectively. The pathways are discussed which lead to stereoisomeric SiN ring compounds by a multiple-step mechanism including zwitterionic intermediates (1,4-dipoles). In addition there is strong evidence for the formation of 1, depending on the trapping reagent used. This fact may be explained by donor→silene interactions. The thermolysis products of silaazetidines support the formulation of a stepwise decomposition to an alkene and Cl2Si=NR derivatives.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 1739-1746 
    ISSN: 0009-2940
    Keywords: Nitrilimines ; Phosphorus heterocycles ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions involving the λ3-phosphorus atom of N-[bis(diisopropylamino)phosphanyl)]-C-[(bis(diisopropylamino) -thio-phosphoranyl)nitrilimine (1) are reported. Addition of elemental sulfur or selenium to 1 leads, by a formal [1 + 4] cycloaddition, to 1,3,4,2λ5-thiadiazaphosphole 3a or 1,3,4,2λ5-selenodiazaphosphole 3b in 85 and 84% yield, respectively. Reactions of 1 with dimethyl acetylenedicarboxylate and tetracyanoethylene afford the corresponding [2 + 4] adducts 1,2,3λ5-diazaphosphinine 6 (80% yield) and 1,2,4,3λ5-triazaphosphinine 10 (80% yield). Phenyl azide reacts with 1 with loss of nitrogen to give 1,2,4,3λ5-triazaphosphole 15 (74% yield), while the reaction of 1 with α-diazo ketone 17 leads with conservation of the N2 grouping to the formation of 1,2,4,3λ5-triazaphosphole 20 (85% yield). Addition of methyl trifluoromethanesulfonate to 1 affords N-[bis(diisopropylamino)methylphosphonioyl]-C-[bis(diisopropylamino)thiophosphoranyl]nitrilimine 22. In contrast to 1, the new stable nitrilimine 22 is strongly electrophilic. [2 + 3] cycloadditions are observed with ethyl vinyl ether, styrene, methyl acrylate and phenylacetylene to furnish the corresponding pyrazolines 23 - 25 and pyrazole 26 in good yields. Water adds to 22 by a 1,3-addition process to give hydrazine 27 (88% yield). The lithium salt 30 of [bis(diisopropyl-amino)thiophosphoranyl](diazo)methane reacts with [bis(pentafluorophenyl)](chloro)phosphane to afford the corresponding diazo compound 32 (50% yield) while the reaction with (chloro)(phenyl)[2,4,6-tris(trifluoromethyl)phenyl]phosphane furnishes nitrilimine 33 in 82% yield. Only 1,3-addition reactions with water or diisopropylamine leading to hydrazine 34 (65% yield) and hydrazone 35 (54% yield) are observed on treatment with this new poorly reactive nitrilimine.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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