About the reaction of β-dimethylamino-α,β-enones with active methylene nitriles
作者:Fathy M. Abdelrazek、Akram N. Elsayed
DOI:10.1002/jhet.181
日期:2009.9
The reaction of 3-dimethylamino-1-arylpropenone derivatives with activemethylenenitriles was reinvestigated and a plausible mechanism to account for the results is suggested. X-ray crystallographic study supported the suggested mechanism. Based on these findings, the reaction of 3-acetylamino-4-dimethylaminobut-3-en-2-one with malononitrile was also reinvestigated and the correct structures verified
Chitosan Based Heterogeneous Catalyses: Chitosan-Grafted-Poly(4-Vinylpyridne) as an Efficient Catalyst for Michael Additions and Alkylpyridazinyl Carbonitrile Oxidation
作者:Khaled Khalil、Hamad Al-Matar
DOI:10.3390/molecules18055288
日期:——
be synthesized under heterogeneous conditions in presence of a potassium persulfate and sodium sulfite redox system. The synthesized graft copolymer could be utilized effectively, in the form of beads, as an efficient catalyst for Michael additions of active methylenes to functionally substituted alkenes. Moreover, methyl moiety oxidation in methyl pyridazinyl carbonitriles by H2O2 in the presence of
Orthoamide. L. Beiträge zur Chemie von Propiolaldehydaminalen - Synthesen und Umsetzungen zu Push-Pull-substituierten Buta-1,3-dienen, Cyclobutanen sowie vinylogen Amidiniumsalzen und 1,2,3-Triazolen
作者:Michael Kiesel、Erwin Haug、Willi Kantlehner
DOI:10.1002/prac.19973390130
日期:——
Tert-butylaminalester 5 reacts with terminal alkynes to give aminals of substituted propiolaldehydes 3c,d. The aminal 3a is accessible from N,N,N,N'-tetramethylformamidinium chloride (7b) and sodium acetylide. The aminals 3b,c can also be prepared from bis(dimethylamino)acetonitrile 8 and terminal alkynes in the presence of sodium hydride. The nitrile 8 is also useful for the preparation of the bis-aminal of acetylenedialdehyde 6. The aminal 3e can be transaminated by heating with secondary amines to give the aminals 3f-i. The aminals 3a-i react with strong CH2-acidic compounds (pK(a) between 9 and 14) to give the 1-dialkylamino-1,3-butadienes 10. The isomeric 1-dialkylamino-butadienes 18 can be obtained from the condensation of the CH-acidic cinnamic acid derivatives 19 with dimethylformamidedimethylacetal. CH and NH-acidic compounds as cyanacetamide react with the aminals 3c,e exclusively with the acidic methylene group to produce the enamines 10h,t. The acylformamidine 21 can be obtained from 10t and tert-butylaminalester 5. The pyridone 22 is accessible from the condensation product 10h by thermal cyclization. The pyrido[2,3-d]pyrimidine 26 is formed in the reaction of the 6-amino-uracile 23 with the aminal 3a. In an unexpected reaction the 1,2-bis(cyano-dialkylaminomethylene)-cyclobutanes 28a-d result from the action of trimethylsilylcyanide on the aminals 3e-h. The corresponding reaction with trimethylsilylisothiocyanate affords the vinylogous amidinium thiocyanates 34a,b. In the reaction of trimethylsilylazide and the aminals 3 are produced the 4-(dialkylaminomethylene)-4H-1,2,3-triazoles 38.