Tri-sec-butylborane is an organoborane compound primarily used in organic synthesis for the transfer of sec-butyl groups. It serves as a precursor to sec-butylboronic acid or ester derivatives, which are employed in cross-coupling reactions, such as the Suzuki-Miyaura coupling, to create carbon-carbon bonds. Its utility in forming these intermediates makes it valuable for the synthesis of complex organic molecules, particularly in pharmaceuticals and fine chemicals. Additionally, as a trialkylborane, it is used in radical chemistry and polymer chemistry. In the presence of oxygen, it generates sec-butyl radicals that initiate polymerization processes, contributing to the production of specialized polymeric materials.