Study of the pyrimidine nucleobase C5C6 bond reactivity under thio‐michael/aldol tandem reaction conditions

Abstract

Pyrimidine nucleobases can undergo a Michael/aldol tandem reaction triggered by a thiolate. In an intramolecular context, 5′‐deoxy‐2′,3′‐isopropylidene‐5′‐thiouridine affords the reminiscent Baylis‐Hillman adduct after retro‐Michael addition whereas its thymine counterpart is unreactive. In an intermolecular context, the conjugate addition‐aldol reaction occurs only if the C5C6 double bond is activated.

Recent Contributions from the Baylis−Hillman Reaction to Organic Chemistry

“…Clivio and co-workers 477 have reported a thiolate-triggered tandem Michael/aldol reaction of pyrimidine nucleobase, which provided Baylis-Hillman adducts, following the reaction sequence shown in Scheme 169. Shibasaki and co-workers 478 have developed a Bacatalyzed direct Mannich-type reaction/isomerization sequenceofβ,γ-unsaturatedestertogiveβ-methylBaylis-Hillman adducts.…”

“…Clivio and co-workers have reported a thiolate-triggered tandem Michael/aldol reaction of pyrimidine nucleobase, which provided Baylis−Hillman adducts, following the reaction sequence shown in Scheme .…”

Intramolecular Morita–Baylis–Hillman and Rauhut–Currier reactions. A catalytic and atom economic route for carbocycles and heterocycles

“…Clivio also investigated similar thio version and found role of sulphur for MBH reaction (eqn (6)). 77 Taneja and co-workers 78 carried out MBH reaction of parthenin (a sesquiterpene) and obtained a mixture of products featuring 1,3-dioxolane moiety which suggested key role of tertiary alcohol during the course of reaction. An example is presented in Scheme 66.…”