Manganese(III), nature’s highest-potential one-electron oxidant (1.23 V vs NHE), plays a central role in biological processes such as photosynthesis and carbon cycling. Despite its natural significance, its high-potential properties in synthetic chemistry remain untapped due to the absence of well-defined, accessible Mn(III) reagents. The Lacy group has overcome this limitation by developing bench-stable high-potential (>1.23 V vs NHE) Mn(III) complexes and is now investigating their reactivity to enable new synthetic methodologies with implications across several disciplines. A significant portion of reactions performed by chemists rely on transition metals. While remarkable progress has been made in using 1st-row metals such as Co, Ni, and Cu for sustainable metal chemistry, these elements are neither as abundant in the Earth’s crust nor as benign to human health as Fe, Ti, and Mn, which are the three most abundant transition metals. Despite their abundance, Mn-based reagents remain underdeveloped relative to Fe and Ti, which benefit from a wealth of stable binary precursors (e.g., TiIVX4, TiIIIX3L, FeIIX2, and FeIIIX3; X = halide or pseudohalide). In contrast, the chemistry of Mn is constrained by the limited availability of binary MnX reagents, which consists of comparatively redox-inert Mn(II) salts, “Mn(OAc)3”, and unreactive mineral-like MnF3. The barrier to expansion is the inaccessibility of binary Mn(III) halides and pseudohalides, such as MnCl3, because they are thermodynamically and kinetically unstable. Though the limited set of Mn starting materials has not prevented the advancement of useful reagents like Mn(OAc)3, KMnO4, Mn(III) salen complexes and other designer catalysts, the absence of Mn(III) halides and pseudohalides (MnIIIX3) from the chemists’ toolbox reveals an intriguing question. Are chemists overlooking potentially transformative compounds and reactivity profiles? There is compelling reason to believe the answer is yes, and this talk will describe these compelling reasons.