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Unexpected One‐Pot Formation of Lactam Oximes from Amino‐Hydroxamic Esters

“…Formation of lactam oximes from the corresponding linear diprotected amino-hydroxamic acids is interesting as it is the only example, to our knowledge, of this kind of condensation reaction happening in a one-pot manner. The described formation of these compounds from an amino compound and a hydroxamic ester involves the use of harsh chlorinating reagents such as PCl 5 [9] or POCl 3 , [10] while the condensation of a lactam with an alkoxyamine has been described with triethyloxonium tetrafluoroborate, [5] or by thionation, [11,12] both cases corresponding to a formal activation of the carbonyl. To facilitate the synthesis of lactam oxime deriva-tives, there is an interest of developing a two-step one-pot cyclisation of amino-hydroxamic esters and we decided to further investigate this unexpected reaction.…”

“…Several lactam oximes other than carbohydrate were also described. Synthesis of lactam oxime from quinolinone, leading to 6-and 7-membered ring derivatives, [5] and from N-oxide pyridines [6] were reported. Besides, quinazolinone-based lactam oximes showed HSP90 inhibiton potency.…”

Synthesis of Cyclic N-Acyl Amidines by [3 + 2] Cycloaddition of N-Silyl Enamines and Activated Acyl Azides

“…The development of synthetic pathways toward cyclic amidine derivatives is a research area of growing interest. Cyclic amidine derivatives have been shown to have interesting biological activities [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]; however, methods for their synthesis have several limitations [ 9 , 10 , 11 ]. Thus, several research groups have been developing synthetic methodologies for these derivatives [ 12 , 13 ].…”

“…Thus, several research groups have been developing synthetic methodologies for these derivatives [ 12 , 13 ]. Although most precedent pathways use cyclic amides as starting materials [ 11 , 12 , 13 ], our group recently reported a novel synthetic strategy that uses the readily available N -heteroarenes as starting materials and proceeds via a versatile N -silyl enamine intermediate ( Scheme 1 a) [ 14 , 15 ]. We achieved this intermediate through the B(C 6 F 5 ) 3 catalyzed dearomative hydrosilylation of N -heteroarene, which is considered an emerging area in organic synthesis [ 16 , 17 , 18 , 19 ].…”

Synthesis, reactions, and antimicrobial activity of 2‐cyano‐N′‐(4‐(2‐oxo‐2‐phenylethoxy)benzylidene)acetohydrazide derivatives

“…[ 6 ] Moreover, a lot of heterocyclic ring systems were prepared through cyanoacetic acid hydrazide like pyrazoles, [ 7,8 ] thiophenes, [ 9–11 ] thiazoles, [ 12,13 ] pyrazolopyrimidines, [ 14 ] pyrimidines, [ 15,16 ] pyridines, [ 17–20 ] and others. [ 21–23 ]…”