SEARCH Articles Figures Tables 1,3-dipolar cycloaddition reactions Diels—Alder reaction 1.3- Dipolar reactions Alder Cycloaddition Cycloaddition reactions 1,3-dipolar Cycloaddition reactions Diels-Alder reaction Cycloadditions 1,3-dipolar reactions Diels cycloaddition Diels cycloaddition reactions Diels-Alder cycloaddition Diels-Alder cycloadditions Diels-Alder reaction 1,3-dipolar cycloadditions Diels-Alder reaction 1,3-dipolar cycloadditions Diels-Alder reaction 2 + 2] cycloaddition Diels-Alder reactions and 1,3-dipolar cycloadditions Porphyrins in Diels-Alder and 1,3-dipolar cycloaddition reactions