Eine einstufige Synthese von γ‐Ketocarbonsäuren

Reinheckel, H.; Haage, K.; Gensike, R.

doi:10.1002/ange.19650771715

Cited by 8 publications

(2 citation statements)

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“…Ether cleavage by strong Lewis acidic group 13 halides is not unusual, but the cleavage reaction usually stops after the first step leading to alkoxides X 2 EOR of group 13 compounds. [63] InϪOϪIn structural units are well known e.g. in organylindium alkoxide or OH-bridged diorganylindium carboxylates.…”

Section: Discussionmentioning

confidence: 99%

Hydrazino Derivatives of Gallanes and Indanes − Synthesis and Structures

Nöth

Seifert

2002

Eur. J. Inorg. Chem.

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The reaction of Me2GaCl with tBuHN−NH2 proceeds with ligand exchange at the gallium atom leading to MeCl2Ga·H2N−NHtBu (1). On the other hand, only one methyl group of the trimethylgallium molecule reacts in refluxing toluene with anhydrous hydrazine in a 4:3 ratio to produce the bicyclic dimethylgallium hydrazide 3. N‐Lithio‐N‐trimethylsilyl‐N′‐2‐naphthylhydrazine reacts with dimethylgallium chloride, not only by introducing a gallium atom into the hydrazine unit, but also by inducing CH activation at the 1‐position of the naphthyl group with methane evolution. The main product isolated is the 2,3‐dihydro‐1H‐naphtho[1,2‐d][1,2,3]diazagallol 4 which proved to be dimeric. A 1:1 GaMe3 adduct of Li(Me3Si)N−NHtBu (5) is the unexpected compound in the reaction of Me2GaCl with Li(Me3Si)N−NHtBu. The expected substitution product Me2Ga(Me3Si)N−NHtBu is not formed. Compound 5 is a dimer in the solid state. The products obtained from reactions of Li(Me3Si)N−NHtBu with Me2InCl depend on the solvent. With hexane as a solvent the dimeric trimethylindium adduct of Li(Me3Si)N−NHtBu (7), is produced as the main species. In diethyl ether the cage compound 8 is isolated which can be regarded as an (Me3SiN=InMe)2 adduct with [Li(Me3Si)N−NHtBu]2. Moreover, the reaction of Me2InCl in diethyl ether with the bulky lithium hydrazide Li[Me3SiN−N(SiMe3)2] leads not to the substitution product, but to the dimeric adduct 9 of a diindoxane, Me2In−O−InMe2 with Li(Me3Si)N−N(SiMe3)2. The formation of this product indicates that ether cleavage or hydrolysis (during crystallization) has occurred.

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Section: Discussionmentioning

confidence: 99%

Hydrazino Derivatives of Gallanes and Indanes − Synthesis and Structures

Nöth

Seifert

2002

Eur. J. Inorg. Chem.

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“…No hydrolysis was observed when other lanthanide derivatives, including the Ce(IV) compounds Ce(SO 4 ) 2 and CeF 4 were used. Since both the reactions of CAN 8 and some other additions to C=N double bonds of imines were shown to occasionally involve free radicals, 9 we performed the ethylation listed as entries 1-3 in Table 1 in the presence of either benzoyl peroxide or AIBN. As neither free radical initiators caused any changes in the rate of ethylation nor altered the ratio between PhCH(Et)NHPh and Ph-CHO, we conclude that the formation of the ethylated amine and of the aldehyde (in the presence of stoichiometric quantities of Et 3 Al) do not involve a free radical mechanism.…”

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Cerium(IV)-Promoted Ethylation of Schiff Bases by Triethylaluminum

Tsvelikhovsky¹,

Schumann²,

Blum³

2006

Synthesis

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C e r i u m ( I V ) -P r o m o t e d E t h y l a t i o n o f S c h i f f B a s e s b y T r i e t h y l a l u m i n u mAbstract: Schiff bases Ar 1 CH=NAr 2 that are refractory towards Et 3 Al are activated at room temperature by cerium(IV) compounds. The ethylation takes place selectively at the methine moiety of the imine. The process is strongly influenced by steric hindrance and depends on the electronic nature of the substrate: electron-donating substituents promote the reaction while electron-withdrawing groups cause it to slow down. Application of cerium(IV) ammonium nitrate as promoter gives the best results. In the absence of excess Et 3 Al it causes, however, transformation of the Schiff base to the corresponding aldehydes and amines.

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