Table 1.

Development of the Tandem Dehydrogenation/Diels-Alder

entry	catalysta	solvent	additivef	dienophilee	yield dieneb	yield cycloadductc
1	Pd(OAc)2	dioxane	-----	-----	<1d	-----
2	1	dioxane	-----	-----	6	-----
3	2	dioxane	-----	-----	28	-----
4	2	dioxane	-----	NPM	<1d	33
5	2	DCE	-----	NPM	<1d	52
6	2	DCE	p-NO2BzOH	NPM	<1d	74
7	2	DCE	p-NO2BzOH	-----	35	-----

^a10 mol% catalyst

^bIsolated after 24 hr as a 4:1 mixture of E/Z isomers along with rSM

^cisolated yield

^dDetermined by GC analysis

^eNPM = N-phenylmaleimide (1.0 equiv.)

^f10 mol%