Pyrazolo isoquinolines, synthesis

Pyrazolo[3,4-d][l,2]diazepines synthesis, 7, 597 Pyrazolop, 4- 6][ 1,4]diazepines synthesis, 5, 272 Pyrazolo[l, 4]diazepinones as anticonvulsant, 1, 170 Pyrazolo[2,3-e]diazepinones synthesis, 5, 272 1 H-Pyrazolo[l,5-6]imidazoles synthesis, 6, 992 Pyrazolo[2,3-a]imidazoles biological activity, 6, 1024 Pyrazolo[2,3-c]imidazoles reactions, 6, 1041 synthesis, 6, 1047 Pyrazolo[2,3-imidazoles synthesis, 6, 991 Pyrazolo[3,2- njisoquinolines synthesis, 5, 339 Pyrazolop, 4-c]isoquinolines synthesis, 5, 273 Pyrazolonaphthyri dines synthesis, 5, 339 Pyrazolone, diazophotolysis, 5, 252 Pyrazolone, 4,4-dihalo-rearrangements, 5, 250 Pyrazolone, ethoxy-hydrazinolysis, 5, 253 Pyrazolone, 4-halo-... 

Furthermore, the pyrazole formation reaction was also combined with a palladium-catalyzed Sonogashira coupling with a terminal alkyne and subsequent intramolecular 6-endo alkyne hydroamination to provide an alternative approach to the facile synthesis of pyrazolo[5,l-a]isoquinoline 36 (Scheme 7.19) [72]. 

Fu and co-workers reported a one-pot copper-catalyzed protocol for the synthesis of lff-pyrazolo[5,l-fl]isoquinolines containing various functional groups (38), which provided opportunity for the constmction of this kind of N-fused heterocycles (Scheme 7.20) [73]. 

Scheme 7.20 One-pot copper-catalyzed synthesis of H-pyrazolo[5,l-a]isoquinolines...

Wu et al. described a Cu(OTf)2-catalyzed reactions of N -(2-alkynylbenzylidene) hydrazides with diethyl phosphite for the synthesis ofisoquinolin-l-ylphosphonate. Some isoquinolin-l-ylphosphonates could be obtained in moderate yield (Scheme 8.92). The C(sp )-H bond of imine was cleaved and new C-P bond was formed [163]. They also reported a AgOTf- and Cu(OAc)2-cocatalyzed cascade reaction of N -(2-alkynylbenzylidene)-hydrazide with allenoate to 2-carbonyl //-pyrazolo[5,l- ]isoquinolines under mild conditions. The AgOTf/Cu(OAc)2 cooperative catalysis is essential for this transformation. The reaction might proceed through a peroxy-copper(III) intermediate [164] (Scheme 8.92). 

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