1013630-63-1Relevant articles and documents
Ring expansion versus cyclization in 4-oxoazetidine-2-carbaldehydes catalyzed by molecular iodine: Experimental and theoretical study in concert
Alcaide, Benito,Almendros, Pedro,Cabrero, Gema,Callejo, Ricardo,Pilar Ruiz,Arno, Manuel,Domingo, Luis R.
supporting information; experimental part, p. 1688 - 1700 (2010/09/09)
Molecular iodine (10 mol%) efficiently catalyzes the ring expansion of 4-oxoazetidine-2-carbaldehydes in the presence of tert-butyldimethylsilyl cyanide, or allylic and propargylic trimethylsilanes to afford protected 5-functionalized-3,4-dihydroxypyrrolidin-2-ones with good yield and high diastereoselectivity, through a C3-C4 bond cleavage of the β-lactam nucleus. Interestingly, in contrast to the iodine-catalyzed reactions of 3-alkoxy-β-lactam aldehydes which lead to the corresponding γ-lactam derivatives (rearrangement adducts), the reactions of 3 aryloxy-β-lactam aldehydes under similar conditions gave β-lactam-fused chromanes (cyclization adducts) as the sole products, through exclusive electrophilic aromatic substitution involving the C3 aromatic ring and the carbaldehyde. In order to support the mechanistic proposals, theoretical studies have been performed.
I2-Catalyzed enantioselective ring expansion of β-lactams to γ-lactams through a novel C3-C4 bond cleavage. Direct entry to protected 3,4-dihydroxypyrrolidin-2-one derivatives
Alcaide, Benito,Almendros, Pedro,Cabrero, Gema,Ruiz, M. Pilar
, p. 615 - 617 (2008/09/21)
Molecular iodine (10 mol%) efficiently catalyzes the ring expansion of 4-oxoazetidine-2-carbaldehydes 1 in the presence of tert-butyldimethyl cyanide to afford protected 5-cyano-3,4-dihydroxypyrrolidin-2-ones 2 with good yield and high diastereoselectivity, through a novel C3-C4 bond cleavage of the β-lactam nucleus. The Royal Society of Chemistry.