Trifluoromethyl-p-tolyldiazomethane in 1,3-dipolar cycloaddition reactions
摘要:
Trifluoromethyl-p-tolyldiazomethane (I) forms [3 + 2]-cycloadducts with activated alkenes and alkynes. The products of these regiospecific reactions are substituted pyrazolines (II)-(VI) and pyrazoles (VIII)-(X). Reaction of (I) with fumarates, trifluoropyruvates and allyl chloride is accompanied by elimination of N2 and formation of a 1,2-bis(trifluoromethyl)stilbene. The results obtained indicate that (I) enters only the HOMO-controlled 1,3-dipolar addition reactions.