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Pyrrolidine catalyzed reactions of cyclopentadiene with ?,?-unsaturated carbonyl compounds: 1,2- versus 1,4-additions.

ABSTRACT: A systematic study of the reactions of cyclopentadiene with ?,?-unsaturated carbonyl compounds in the presence of catalytic pyrrolidine-H2O revealed that the reactions can either proceed with a Michael attack at the ?-carbon of enone, or 1,2-addition to the carbonyl, leadingeither to 4-cyclopentadienyl-2-butanones or 6-vinylfulvenes. The former can be isolated and/or converted to the corresponding 1,2-dihydropentalenes with base (or in one-pot at longer reaction times). Substitution pattern on the enones on the competing pathways have been studied and consistent mechanisms are proposed.

SUBMITTER: Coskun N

PROVIDER: S-EPMC4403802 | biostudies-literature | 2015 May

REPOSITORIES: biostudies-literature

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Pyrrolidine catalyzed reactions of cyclopentadiene with α,β-unsaturated carbonyl compounds: 1,2- versus 1,4-additions.

Coskun Necdet N Çetin Meliha M Gronert Scott S Ma Jingxiang J Erden Ihsan I

Tetrahedron 20150501 18

A systematic study of the reactions of cyclopentadiene with α,β-unsaturated carbonyl compounds in the presence of catalytic pyrrolidine-H<sub>2</sub>O revealed that the reactions can either proceed with a Michael attack at the β-carbon of enone, or 1,2-addition to the carbonyl, leadingeither to 4-cyclopentadienyl-2-butanones or 6-vinylfulvenes. The former can be isolated and/or converted to the corresponding 1,2-dihydropentalenes with base (or in one-pot at longer reaction times). Substitution p ...[more]

PMID: 25908883

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