Mechanisms of nucleophilic addition to activated double bonds: 1,2- and 1,4-Michael addition of ammonia

1993 ◽  
Vol 115 (18) ◽  
pp. 8263-8269 ◽  
Author(s):  
Leonardo Pardo ◽  
Roman Osman ◽  
Harel Weinstein ◽  
James R. Rabinowitz
2018 ◽  
Vol 24 (1) ◽  
pp. 23-26
Author(s):  
Zheng Li ◽  
Wenli Song ◽  
Jiaojiao He ◽  
Yan Du ◽  
Jingya Yang

Abstract An efficient method for the synthesis of the title compounds by reactions of divinyl ketones with thiourea is described. This protocol has the advantages of high yields, mild reaction conditions and simple work-up procedure.


2010 ◽  
Vol 82 (7) ◽  
pp. 1555-1568 ◽  
Author(s):  
Valerio Zanotti

Diiron complexes containing C3 ligands, such as vinyliminium and vinylalkylidene bridging units, display unusual reaction patterns, not observed when the same organic fragments are bound to a single metal center, or not coordinated. Bridging vinyliminium complexes [Fe2{μ-η1:η3-C(NMe2)CH=CR}(μ-CO)(CO)(Cp)2][SO3CF3] undergo nucleophilic addition at the iminium C or at α-C position, which is uncommon since non-coordinated vinyliminium species generally undergo conjugated (Michael type) nucleophilic attack. Likewise, bridging vinyliminium ligands undergo new and unusual transformations consisting of the deprotonation and replacement of the α-CH by a variety of functional groups. These reactions, resulting in the formation of C–C and C–heteroatom single and double bonds, produce new bridging ligands of the type [μ-C(NMe2)C(X)CR) (X = S, O, Se, SPh, CNMe, NNCHCO2Me]. Removal of the vinylalkylidene ligands from the bridging coordination is achieved by a [3 + 2] cycloaddition with alkynes. The reaction leads to the formation of ferrocenes containing one polysubstituted Cp ring, which results from the cycloaddition of the bridging C3 ligand with alkynes. This result suggests a new possible route for the synthesis of polyfunctionalized ferrocenes.


2014 ◽  
Vol 10 ◽  
pp. 722-731
Author(s):  
Natalia V Pavlenko ◽  
Tatiana I Oos ◽  
Yurii L Yagupolskii ◽  
Igor I Gerus ◽  
Uwe Doeller ◽  
...  

A series of novel (1-aminoalkyl)(trifluoromethyl)- and -(difluoromethyl)phosphinic acids – analogues of proteinogenic and nonproteinogenic α-amino acids were prepared. The synthetic methodology was based on nucleophilic addition of (trifluoromethyl)phosphinic acid or (difluoromethyl)phosphinic acid or its ethyl ester to substrates with C=N or activated C=C double bonds. Analogues of glycine, phenylglycine, alanine, valine, proline, aminomalonic and aspartic acids were thus prepared. Three-component one-pot reactions of (trifluoromethyl)phosphinic acid and dibenzylamine with aldehydes were also tested to prepare the title compounds.


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