bearing electron-donating groups (o-Me, m-OMe, m-Me, p-Me) furnished the corresponding products (3b-3d, 1f) in high yields (83%-86%). However, BCBs 1e and 1g bearing electron-withdrawing groups (m-Cl, p-F) reduced the yields (69%). Notably, the BCB substituted with p-CF3 only provided a trace amount of the desired product. Moreover, ethyl substituted BCB 1h can also maintain high yield (84%). Apart from BCB esters, N,N-dimethyl-3-phenylbicyclo[1.1.0]butane-1-carboxamide, monosubstituted BCB sulfones and monosubstituted BCB ketone were evaluated, but no reaction occurred. Moreover, disubstituted BCB ketone and BCB containing an acyl pyrazole group gave complex reaction mixtures. (details were shown in Supporting Information). Attention was then paid to the benzofuranderived oxadienes. An array of benzofuran-derived oxadienes 2b-2h, bearing either electron-donating or electron-withdrawing groups on the ortho (o-Me, o-Br), meta (m-Me, m-F), and para positions (p-Me, p-I, p-CF3) of phenyl rings (R 4 ), gave products in good yields (3i-3o, 72%-78% yields). It was noteworthy that 3,5-diMe and 3,4-diCl substituted substrates 2i and 2j underwent the reaction smoothly, affording the target products 3p (70% yield) and 3q (68% yield), respectively. Benzofuran-derived oxadienes 2k and 2l, featuring a heteroaryl R 4 group (2furyl) and a fused-ring R 4 group (α-naphthyl), also reacted smoothly, producing 3r and 3s with yields of 64% and 60%. However, benzofuran-derived oxadiene with aliphatic R 4 group (cyclohexyl) gave a complex reaction mixture (details were shown in Supporting Information). The influence of the R 3 group on the benzofuran-derived oxadienes was also investigated, the reactions of benzofuran-derived oxadienes 2m, 2o-2q bearing various substituents (5-Br, 6-F, 7-OMe and 7-Br) of the benzofuran ring also effciently proceeded to afford the target products 3t, 3v-3x in 65-87% yields. It is worth noting that the methoxyl group on the C6 position failed to give the desire product and BCB 1a was completely decomposed into cyclobutene (details were shown in Supporting Information). Nevertheless, the 2n bearing a methyl group at the C6 position could engage in the reaction to produce 3u, albeit with reduced yield (44%). The structure of 3a was unambiguously determined X-ray single crystal diffraction, and the configurations of other products were assigned by analogy.