Table 1.

Oxidation of α,β-Unsaturated Carbonyl Compounds by T-HYDRO® catalyzed by Rh₂(cap)₄.^a

Entry	Substrate	Product	Equiv. TBHP	%Yield b
1			10.0 8.0	84 76
2			10.0	76
3			10.0	87
4			10.0 8.0	85 82
5			8.0	65
6			8.0	70
7			8.0	64
8			8.0	32

^aReactions were performed with 1.36 mmol of substrate in 2.5 mL of DCE to which was added 4.0 or 5.0 equiv of TBHP (70% in water) and 0.50 mol % Rh₂(cap)₄ and the solution was heated at 40 °C. After 16 hours an additional 4.0 or 5.0 equiv of TBHP (70% in water) and 0.50 mol % Rh₂(cap)₄ was added, and reaction was continued for an additional 24 hours.

^bIsolated yield after column chromatography; carboxylic acids were purified by recrystallization from ethyl acetate and the mass yield after recrystallation is given.