Abstract
Michael addition of allylsulfone carbanions to nitroolefins where shown to be sensitive to substitution in both the donor and the acceptor. While sulfone 10 gave predominantly products of γ-addition with aromatic nitroolefins, addition to aliphatic nitroolefins produced almost exclusively α-adducts. In the presence of an OH function in the sulfone (see 13) only (Z) γ-adducts were observed, while a bromine substituent reversed the regiochemistry.
Original language | English |
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Pages (from-to) | 2741-2744 |
Number of pages | 4 |
Journal | Tetrahedron Letters |
Volume | 33 |
Issue number | 19 |
DOIs | |
State | Published - 5 May 1992 |
Bibliographical note
Funding Information:double bond in 15 - 17 in a more selectivem anner than in sulfone 10. This coordinationa ffectsa lso charged istributionl eadingt o greaterp referencef or r-attack.A contrarye ffectc ould be expectedin 14, in which charged elocalizationa t the CH2 terminus,d ue to the participationo f allylic bromine, should enhancea ttacka t the sulfone-substitutecda rbon,l eadingt o 18 - 19,r espectivelyS. tudiesa re continuing for the rationalizationo f the substitutionin fluence,w ith emphasiso n the unprecedentede ffecto f allylic substituentse quallyd istancedf rom the reactivet ermini. This should contributet o the exploitationo f suchr eactionsf or new and selectives yntheticr outes. AcknowledgementS: upport of this research by a grant from the US-Israel Binational Science Foundationi s gratefullya cknowledged.
Funding Information:
Acknowkdgement: Support of this research by a grant from the US-Israel Binational Science Foundationi s gratefullya cknowledged.
Funding
double bond in 15 - 17 in a more selectivem anner than in sulfone 10. This coordinationa ffectsa lso charged istributionl eadingt o greaterp referencef or r-attack.A contrarye ffectc ould be expectedin 14, in which charged elocalizationa t the CH2 terminus,d ue to the participationo f allylic bromine, should enhancea ttacka t the sulfone-substitutecda rbon,l eadingt o 18 - 19,r espectivelyS. tudiesa re continuing for the rationalizationo f the substitutionin fluence,w ith emphasiso n the unprecedentede ffecto f allylic substituentse quallyd istancedf rom the reactivet ermini. This should contributet o the exploitationo f suchr eactionsf or new and selectives yntheticr outes. AcknowledgementS: upport of this research by a grant from the US-Israel Binational Science Foundationi s gratefullya cknowledged. Acknowkdgement: Support of this research by a grant from the US-Israel Binational Science Foundationi s gratefullya cknowledged.
Funders | Funder number |
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US-Israel Binational Science Foundationi s gratefullya cknowledged | |
US-Israel Binational Science Foundationi s gratefullya cknowledged |
Keywords
- Michael reactions
- allylic anions
- nitroolefins
- sulfones