Journal of the American Chemical Society, Vol.120, No.10, 2218-2226, 1998
Activation of styrenes toward Diels-Alder cycloadditions by osmium(II) : Synthesis of stereodefined decalin ring systems
The complex [Os(NH3)(5)(eta(2)-anisole)](2+) reacts with acetals or Michael accepters to form 4-methoxystyrene complexes that are exclusively coordinated at the arene (eta(2)) These styrene complexes are active dienes and readily participate in Diels-Alder reactions with electron-deficient olefins to form tetrahydronaphthalene complexes. The cycloadducts are formed typically as single diastereomers and are valuable as precursors to functionalized tetralins and decalins.
Keywords:CYCLO-ADDITION REACTIONS;STEREOSELECTIVE SYNTHESES;COMPLEXES;DIENOPHILES;EQUIVALENT;(ETA-5-C5H5)FE(CO)2(ETA-1-C5H5);ETA(2)-PYRROLE;CONVERSION;EFFICIENT