Next, we examined tetraborylethene 6 with styrene under the same EnT cycloaddition reaction conditions (see pathway for III to III-3 in Figure ). Remarkably, the reaction proved to be applicable to the tetraborylethene 6 with styrene 2a, resulting in the formation of the tetra-borylated cyclobutane product (7a) in a 54% (Figure ). This reaction exhibited good tolerance to different substituted styrene such as alkylated arene 2b and chlorine arene 2d resulting in moderate yields. Notably, the structure of tetra-borylated cyclobutane product 7b was clearly determined by X-ray crystallographic analysis (please see the X-ray structure of 7b in Figure ). Additionally, 1-naphthalene 2h was also a suitable arylated olefin, affording the desired tetraborylated cyclobutane product 7d in a 44% yield (Figure ).