Synthesis of Benzannelated 1-Azacycl[3.2.2]azine: 1-Azabenzo[h]cycl[3.2.2]azine

Aminoacid-derived mercaptoimidazoles

“…We could, however, overcome this poor reactivity by using the methylsulfanyl imidazole 17. The latter was readily converted to the unsubstituted imidazole by treatment with Raney nickel 19 in refluxing ethanol overnight as shown in Scheme 5.…”

Indolizines and Their Hetero/Benzo Derivatives in Reactions of [8+2] Cycloaddition

“…Soon it was proved also for 8-aza-indolizine 60a and its 7-oxo-analog 61b [ 85 ]. 1-Azaindolizine bearing 2-SO 2 Me group failed to go in such cycloaddition [ 86 ], whereas the same structures with 2-SMe group 61a , b [ 87 ] and their [h]-benzannelated derivatives 62 [ 88 ] formed the desired azacyclazines with DMAD. In our recent work, we proved that MAC could react with 1-azaindolizine 63 giving azacyclazine in the open air [ 36 ].…”

“…1.8-Annelatyed indolizines gave purple 3-vinyl adducts 91 with DBZA [ 46 ] which underwent further dehydrogenation without cyclization (see Scheme 9 ). Benzoindolizines 92 [ 29 ] and their aza-derivative 93 [ 88 ] even in presence of catalysis gave the adducts together with cyclazines. 2-Isopropenyl indolizine 94 after prolonged heating with DMAD gave the mixture of isomeric 3-vinyl derivatives [ 109 ].…”