- Conformational arm-wrestling: Battles for stereochemical control in benzamides bearing matched and mismatched chiral 2- and 6-substituents
-
The orientation of a tertiary amide group adjacent to an aromatic ring may be governed by the stereochemistry of an adjacent chiral substituent. With a chiral substituent in both ortho positions, matched/mismatched pairs of isomers result. Evidence for ma
- Clayden, Jonathan,Foricher, Yann J. Y.,Helliwell, Madeleine,Johnson, Paul,Mitjans, David,Vinader, Victoria
-
-
Read Online
- Directed: Ortho-metalation-nucleophilic acyl substitution strategies in deep eutectic solvents: The organolithium base dictates the chemoselectivity
-
Directed ortho metalation (DoM) or nucleophilic acyl substitution (SNAc) can be efficiently programmed on the same aromatic carboxylic acid amide, in a choline chloride-based eutectic mixture, by simply switching the nature of the organolithium reagent. Telescoped, one-pot ortho-lithiation/Suzuki-Miyaura cross-couplings have also been demonstrated for the first time in Deep Eutectic Solvents.
- Ghinato, Simone,Dilauro, Giuseppe,Perna, Filippo Maria,Capriati, Vito,Blangetti, Marco,Prandi, Cristina
-
supporting information
p. 7741 - 7744
(2019/07/12)
-
- Phthalide: A direct building-block towards P,O and P,N hemilabile ligands. Application in the palladium-catalysed Suzuki-Miyaura cross-coupling of aryl chlorides
-
The direct synthesis of new hemilabile ligands from the economical, readily available lactone phthalide is described. Pd-complexes of one such ligand were found highly effective in general Suzuki-Miyaura cross-coupling reactions, including deactivated and hindered aryl chlorides. The Royal Society of Chemistry 2013.
- McNulty, James,Keskar, Kunal
-
supporting information
p. 2404 - 2407
(2013/06/05)
-
- Synthesis of atropisomeric diamides with remotely related stereogenic axes by stereoselective additions to imines
-
Atroposelective addition of axially chiral laterally lithiated 2-alkyl- 1-naphthamides to 6-substituted 2-(N-methylformimino)benzamides leads, after equilibration of the new stereogenic axis to its more stable conformation, to single atropisomeric diaster
- Clayden, Jonathan,Westlund, Neil,Wilson, Francis X.
-
p. 3331 - 3334
(2007/10/03)
-
- Sparteine-mediated enantioselective [2,3]-Wittig rearrangement of allyl ortho-substituted benzyl ethers and ortho-substituted benzyl prenyl ethers
-
The (-)-sparteine-mediated enantioselective [2,3]-Wittig rearrangement of N,N-dialkyl-o-allyloxymethylbenzamides and o-substituted benzyl prenyl ethers has been investigated. Enantiomeric excess up to 60% was observed as for the reaction with N,N-diethyl-o-allyloxymetylbenzamide. From the mechanistic investigations, it was suggested that the stereoinformation was introduced at the deprotonation step. Substoichiometric amount of (-)- sparteine (0.2 equiv.) did not decrease the enantioselectivity. Introduction of functional groups other than carbamoyl group did not enhance the enantioselectivity in this rearrangement.
- Kawasaki, Takeshi,Kimachi, Tetsutaro
-
p. 6847 - 6862
(2007/10/03)
-
- Enantioselective [2,3]-Wittig rearrangement via sparteine-mediated lateral metalation of N,N-dialkyl-o-allyloxymethylbenzamides and o-substituted benzyl prenyl ethers
-
The (-)-sparteine-mediated enantioselective [2,3]-Wittig rearrangement of N,N-dialkyl-o-allyloxymethylbenzamides and o-substituted benzyl prenyl ethers has been investigated. With N,N-diethyl-o-allyloxymethylbenzamide, enantiomeric excess up to 60% was observed in pentane. These results suggest that the carbamoyl group can effectively assist the transfer of stereoinformation by coordinating with the (-)-sparteine-n-BuLi complex. Other functional groups (OMe, OCONR2, OMOM, F) were impotent to the enantiodifferentiation of this rearrangement.
- Kawasaki, Takeshi,Kimachi, Tetsutaro
-
p. 1429 - 1431
(2007/10/03)
-
- 1-(Dialkylamino)isobenzofurans: Generation and Use for Annelation of Aromatic Rings
-
Three methods are reported for the generation of the heretofore unreported 1-(dialkylamino)isobenzofurans.These are (1) metal-catalyzed decomposition of an o-(diazomethyl)benzamide (9 to 3), (2) fluoride-induced α elimination of an o-benzamide (48 to 3), and (3) deprotonation of a cyclic imidate salt (51 to 3).The first two reactions are consistent with the intermediacy of a carbene.The precursors for all three approaches can be synthesized from tertiary benzamides by ortho-lithiation strategies.Reaction of the transient 1-(dialkylamino)isobenzofurans with dieneophiles in a ?4s + ?2s cycloaddition is the key step in a one-pot sequence that provides annelation of an aromatic ring by a 2,3-substituted 1-(dialkylamino)-4-hydroxycyclohex-1-ene ring.The sequence of formation of the 1-(dialkylamino)isobenzofuran, regio- and stereospecific cycloaddition, ring opening, and proton transfer, is illustrated by the preparations of 15-23, 32, and 33 from N,N-diisopropylbenzamides.The ring annelation is extended to naphthalene and pyridine rings to provide 40, 41, and 44, respectively.Transformations of annelated products to higher and lower oxidation states are reported.
- Chen, Chin-Wen,Beak, Peter
-
p. 3325 - 3334
(2007/10/02)
-