Furthermore, an α-methyl carbamate showed selective oxidation almost exclusively at the less substituted site (11b, 76% yield). With a phenyl-substituted carbamate, the oxidation selectivity was lower still preferring dehydrogenation at the less bulky side (12b). Seven membered aliphatic N-heterocycles, such as 15b, undergo the same reaction. Notably, carbamates tethered with natural products, and drugs, such as (-)-borneol (16b), (3r,5r,7r)adamantane -1-carboxylic acid (17b), camphanic chloride (18b), menthol (19b), 3-( Nitrogen-protected 4-piperidinones are the second class of starting materials that are photocatalytically dehydrogenated in good to excellent yields. The scope comprises various piperidinone derivatives (26-37b, 26b with product yields of up to 83%). The observed regioselectivity indicates that the formation of the less substituted alkene is favoured as shown for compound 29b, which was obtained in 82% yield. Note that a synthesis of 29b by other methods is difficult. Next, we moved our attention to more complex molecules. Piperidinones merged with cis-pinonic acid, 3-(methoxycarbonyl) bicyclo [1.1.1] pentane-1-carboxylic acid, bicyclo[2.2.2]octane-1-carboxylic acid, and (+)-menthyl chloroformate, bearing βsubstituents, were regioselectively dehydrogenated to provide single regioisomeric dihydro-4pyridone derivatives 33b, 34b, 35b, and 36b, respectively, in excellent yields. A derivative of dehydrocholic acid, an unnaturally occurring steroid, was smoothly desaturated yielding compound 37b. The N-protection with pyrimidine gave 38b in 47% yield while N-protection with benzyl and methyl did not work (39-40b) probably due to the high electron density on the nitrogen atom, which may intercept the photocatalytic cycle by reducing the iridium photocatalyst. To demonstrate the scalability of our methodology, a gram scale reaction was performed. Compound 26a was desaturated on 500 mg scale giving the product in 76% yield, which is slightly lower compared to the small-scale reaction (83%).