In addition, different types of substituted olefins (2i-j) were explored. For example, the use of dienes (2i); 10 such as using dimethyl butadiene yielded product 3i in 82%. The reaction also demonstrated fruitful applicability to gem-diborylalkene 1a with α-substituted styrenes 2j, giving product 3j in good yield, allowing the construction of gem-cyclobutanes with all-quaternary carbon (Figure ). It is important to highlight, that all diasteriomeric cyclobutanes products (3a-j) were separated by column chromatography and their structures and the relative syn-and anti-configuration were unambiguously determined by 2D-NMR NOESY studies (of 3a-j, see Supporting Information for more details, pages S239-254).