Investigation of tandem reaction using advantage of the characteristics of the unsaturated bond

各种反式-2,3-二取代-2,3-二氢-4-喹诺酮类化合物通过hofmann型串联重排、异氰酸酯中间体上醇的亲核加成、分子间[2+2]环加成和分子内氨基环化合成。在无金属条件下，通过相同的卤代烯酮中间体，由(Z)或(E)共轭乙酸乙酯与NXS制备多取代呋喃。新的碳-碳三键裂解反应在NIS和TMSN3中有效进行，得到相应的中高收率腈。

Various trans-2,3-disubstituted-2,3-dihydro-4-quinolones have been synthesized via tandem Hofmann-type rearrangement, nucleophilic addition of alcohols to the isocyanate intermediates, intermolecular [2+2]-cycloaddition, and intramolecular aminocyclization. Multisubstituted furans were readily prepared from (Z)- or (E)-conjugated enynyl acetates with NXS under metal-free conditions via the same haloallenyl ketone intermediates. A new cleavage reaction of carbon-carbon triple bonds proceeds efficiently with NIS and TMSN3, giving the corresponding nitriles in moderate to good yields.