1,3-Dipolar Cycloaddition (Part II): Three-Component Cu(I) Catalysed Click Reactions

Cu(I) kataliziranim reakcijama sulfonil- odnosno fosforil-azida i terminalnih alkina nastaje intermedijar ketenimin koji reagira s nukleofilima kao što su voda, alkoholi, amini, piroli ili indoli, pri čemu nastaju odgovarajući amidi, imidati, amidini i supstituirani heterocikli, u jednom reakcijskom koraku. Te selektivne reakcije zbivaju se pri blagim reakcijskim uvjetima (sobna temperatura, prisustvo zraka i vode), bez steričkog i elektronskog utjecaja supstituenata na ishod reakcije.The Cu(I) catalysed reaction of sulfonyl or phosphoryl azide and terminal alkyne obtains a ketenimine intermediate that reacts with nucleophiles like water, alcohols, amines, imines, pyrroles or indoles producing corresponding amides, imidates, amidines and substituted heterocycles, in one reaction step. These selective reactions are characterised by mild reaction conditions (room temperature, presence of air and water), without steric or electron influence of substituents on the reaction outcome

1H-N. M. R. study of the syn! anti ratio of oximes and 2,4- dinitrophenyl hydrazones determined by ASIS and LIS methods

Starting from 1-chloro-butane-2-one (I) and 3-chloro-butane- 2-one (II), oximes Illa, b and IV as well as 2,4-dinitrophenyl hydrazones Va, b and VI were prepared. 'H-nmr spectra show that I gives a mixture of isomeric oximes Illa and IIIb (21 : 79) and 2,4-dinitrophenyl hydrazones Va and Vb (20 : 80). From ketone II only anti isomers IV and VI were obtained. Signals were assigned using ASIS method. From paramagnetic shifts obtained by LIS method it was concluded that unshared pair of nitrogen electrons participates in complex formation with rare earth atom