Die Reaktion von 5-Methyl-o-chinolacetaten mit Nucleophilen

Zusammenfassung 2,5-Dimethyl-o-chinolacetat reagiert mit einer BaseB in der Weise, daßB in die 5-Methylgruppe eintritt. Man erhält so 2-Methyl-5-(B-methyl)-phenole. Ebenso gibt 2,3,5-Trimethyl-o-chinolacetat 2,3-Dimethyl-5-(B-methyl)-phenole. Der Reaktions-mechanismus wird diskutiert.Diese Arbeit sollte meinem verehrten Lehrer und Freund Prof. Dr.A. Franke zu seinem 90. Geburtstage (19. Februar 1964) meine Dankbarkeit bezeugen. Er ging aber zum Schmerze seiner Freunde am Neujahrstage 1964 von uns.     

Die Addition von Nucleophilen an Alkinderivate mit Push-pull-Gruppen

The preparative aspects of the addition of nucleophiles to alkyne-derivatives having both push- and pull-groups ( 1 ) are discussed: The addition of primary and secondary amines as well of aliphatic alcohols to the alkyne-derivatives 1 in most cases predominantly yields the Michael-adducts 2 – 10 . The importance of a side-reaction consisting in an addition of amines to C(2) of the alkyne-derivatives 1 increases in the series 1c ? 1b < 1a and is controlled by stereoelectronic effects. The spectroscopic properties of the compounds 2 – 10 are given.     

Der Mechanismus der Addition von Nucleophilen an Alkinderivate mit Push-pull-Gruppen

The mechanism of the addition of nucleophiles to alkyne-derivatives 1 having both push- and pull-groups yielding Michael-adducts is investigated. The rate of the second-orderreaction increases (a) with increasing nucleophilic character of the amine and alcohol respectively, (b) with increasing electrophilic character of the alkyne-derivatives 1 , and (c) with increasing solvent polarity. These results support as rate-determining step an attack of the nucleophile at C(3) of the alkyne-derivatives.     

Reaktionen von 3-substituiertem 5-Trifluormethyl-1,3,4-oxadiazol-2(3H)-on mit Nucleophilen

Reactions of 3-Substituted 5-Trifluoromethyl-1,3,4-oxadiazol-2(3H)-one with Nucleophiles The 3-substituted 5-trifluoromethyl-1,3,4-oxadiazolones 3, 4, 13 , and 15 are attacked by N- and S-nucleophiles either at the ring C-atom C(2) or C(5). Depending on the nature of the substituent and the nucleophile, the ring-opening products 7, 10, 12 , and 14 or the ring-enlargement products 16 are formed. The reaction of 4 with thiols is a novel variant of the Grob-type fragmentation. The reactivity of the 1,3,4-oxadiazolones is compared with that of the analogous 1,3,4-thiadiazolones. The structures of the new compounds were elucidated by ¹H- and ¹³ C-NMR spectroscopy.     

Ringtransformationen von 3-substituiertem 5-Trifluormethyl-1,3,4-thiadiazol-2(3H)-on mit Nucleophilen

Ring Transformations of 3-Substituted 5-Trifluoromethyl-1,3,4-thiadiazol-2(3H)-one with Nucleophiles The 3-chlormethyl-5-trifluoromethyl-1,3,4-thiadiazolone 3 undergoes a ring transformation to 3-acylated 2,3-dihydro-1,3,4-thiadiazoles 4 with many nucleophiles. Upon formal replacement of the chloromethyl group in the 3-position of 3 by an extended bromoalkyl chain (→9a-c) , the reaction with nucleophiles yields 4-acylated 5,6-dihydro-4H-1,3,4-thiadiazines 10 (from 9a ), 4,5,6,7-tetrahydrothiadiazepines 13 (from 9b ) and 5,6,7,8-tetrahydro-4H-1,3,4-thiadiazocines 14 (from 9c ) by ring enlargement. The 3-propargyl-thiadiazolone 17 rearranges with nucleophiles to 4-acylated 6-methylidene-5,6-dihydro-4H-1,3,4-thiadiazines 18 . The structures of the new compounds were elucidated by ¹H- and ¹³C-NMR spectroscopy.     

Zur Umsetzung des Zweikomponentensystems Trialkylphosphit/Tetrachlorkohlenstoff mit Nucleophilen 3. Die Reaktion in Gegenwart von Ammoniumsalzen

Reaction of the Two-component System Trialkylphosphite/Carbon Tetrachloride with Nucleophiles. 3. Reaction in Presence of Trialkylammoniumsalts Alkali pseudohalogenides (KSCN, NaN₃, KCN) react with the two component system trialkyl phosphite/carbon tetrachloride in presence of trialkylammonium halogenides. Isothiocyanates of dialkylphosphorus acid, N-alkyl phosphoric acid diester amides, N-dialkoxyphosphoryl trialkoxy phosphazenes and tricyano phosphane oxide respectively, are obtained. In the system (RO)₃P/CCl₄/R₃NHI the dialkoxy phosphoryl chloride is formed.     

Reaktionen des Cumalinsäure-methylesters und Cumalinaldehyds mit ambidenten Nucleophilen

Reactions of Methyl Coumalate and Coumalaldehyde with Ambident Nucleophiles Methyl coumalate and coumalaldehyde show great diversity in their reactions with ambident nucleophiles both depending upon the 2H-pyran-2-one derivative and the nature of the ambident nucleophile used. The products are either pyridine or pyrimidine derivatives.     

Zur Umsetzung des Zweikomponentensystems Trialkylphosphit/ Tetrachlorkohlenstoff mit wasserstoffhaltigen Nucleophilen 2. Die Reaktion mit Ammoniak und Aminen

Reaction of the Two-component System Trialkylphosphite/Carbon Tetrachloride with Nucleophiles Containing Hydrogen. 2. Reaction with Ammonia and Amines Ammonia and primary amines react with the two-component system trialkylphosphite/carbon tetrachloride yielding diester-amides of phosphoric acid, (RO)₂P(O)NHR′. If an excess of amine is used compounds of the type ROP(O)(NHR′)₂ and OP(NHR′)₃ are formed too. By the reaction of (RO)₃P/CCl₄ in presence of secondary and tertiary amines the first reaction product is (RO)₂P(O)CCl₃ which yields with the amine [NRR′R″R″′]⁺[Cl₃CP(OR)O₂]^?; (R = Et, Bu).     

Zur Umsetzung des Zweikomponentensystems Triethylphosphit/Tetrachlorkohlenstoff mit wasserstoffhaltigen Nucleophilen 1. Die Reaktion mit Säureamiden

Reaction of the Two-component System Triethylphosphite/Carbon Tetrachloride with Nucleophiles Containing Hydrogen. 1. Reaction with Acyl Amides Acyl amides react with the two-component system triethylphosphite/carbon tetrachloride yielding N-acyl phosphazenes, (EtO)₃P?N? Ac. In this way (EtO)₃P?N? P(O)(OEt)₂, (EtO)₃P?N? CN, (EtO)₃P?N? C(O)Ph, and (EtO)₃P?N? SO₂Ph were prepared. Ethyl esters of phosphoric acid and trichloromethane phosphonic acid were obtained as by-products.     

Über die relative Reaktivität von Nucleophilen. Vorläufige Mitteilung

For a number of nucleophiles L an approximate linear correlation between the logarithms of the stability constants of methylmercury-complexes of L and the nuclear spin-spin-coupling constants J of Ch₃HgL was found.