Table 5. Screening of Conditions^a.

entry	atmosphere	solvent	convb (%)	yieldc,d (%)
1	argon	pinacolone	86	69 [64]
2	argon	acetone/dioxane (1:1)	82	62
3	argon	cyclohexanone	83	61
4	argon	acetophenone	80	61
5	air	pinacolone	91	73 [61]
6	CO	pinacolone	65	43
7	H2	pinacolone	97	93 [91]
8	argone	3-ethyl-3-pentanol	96	45
9	argonf	pinacolone	99	59 [53]

^aReaction conditions: 4a (0.5 mmol), 6a (0.75 mmol), Ru₃(CO)₁₂ (5 mol %), and pinacolone (0.5 mL).

^bConversion based on GC analysis with respect to 4a (dodecane as internal standard).

^cYield determined by GC analysis with respect to 4a (dodecane as internal standard).

^dNumber in brackets is yield of 5a.

^eThe reaction was performed in a vial with septum and argon balloon.

^fMicrowave reaction: 170 °C for 2.5 h.