Categories: C-C Bond Formation > Oxygen-containing molecules > Carboxylic Acids and Derivatives
A Au(I)-catalyzed hydroalkoxylation/Claisen rearrangement cascade reaction of aryl ynol ethers and ynamides with allylic alcohols provides γ,δ-unsaturated esters or amides, respectively. The [Au(IPr)NTf2] catalyst is most effective for this reaction, and the reaction proceeds under mild conditions in an atom-economical way.
S. Misawa, A. Miyairi, Y. Oonoshi, S. P. Nolan, Y. Sato, Synthesis, 2021, 53, 4644-4645.
Copper-catalyzed allylic alkylation of ketene silyl acetals proceeds with excellent γ-E-selectivity. In reactions of enantioenriched secondary allylic phosphates, an efficient α-to-γ chirality transfer with anti-selectivity can be achieved. The reaction was readily scalable and highly reliable in terms of product yield and stereoselectivities.
D. Li, H. Ohmiya, M. Sawamura, Synthesis, 2012, 44, 1304-1307.
Diallyl 2-alkyl-2-arylmalonates underwent palladium-catalyzed decarboxylative allylation quickly under mild conditions. In contrast, no reaction took place with diallyl 2,2-dialkylmalonates under the same conditions. Electron-donating phosphine ligands were found to be vital for this reaction.
D. Imao, A. Itoi, A. Yamazaki, M. Shirakura, R. Ohtoshi, K. Ogata, Y. Ohmori, T. Ohta, Y. Ito, J. Org. Chem., 2007, 72, 1534-1537.
Cooperative catalysis facilitates the direct asymmetric α-allylation of readily available aryl acetic acid esters. Since enantioselection is determined by a chiral nucleophile, this conceptual approach to cooperative catalysis constitutes a potentially general solution to the direct catalytic asymmetric α-functionalization of acyclic esters.
K. J. Schwarz, J. L. Amos, J. C. Klein, D. T. Do, T. N. Snaddon, J. Am. Chem. Soc., 2016, 138, 5214-5217.
The tandem ylide formation/[2,3]-sigmatropic rearrangement between donor/acceptor rhodium carbenoids and chiral allyl alcohols generates two vicinal stereogenic centers in a convergent C-C bond forming process. Any of the four possible stereoisomers can be selectively synthesized by appropriate combination of the chiral catalyst Rh2(DOSP)4 and the chiral alcohol.
Z. Li, B. T. Parr, H. M. L. Davies, J. Am. Chem. Soc., 2012, 134, 10942-10946.
Chelated amino acid ester enolates are excellent nucleophiles for allylic alkylations. With these enolates, even terminal π-allyl palladium complexes react without significant isomerization.
K. Krämer, U. Kazmaier, J. Org. Chem., 2006, 71, 8950-8953.
Cocatalysis between a chiral Ir-(phosphoramidite,olefin) complex and La(OTf)3 enables enantioselective bond formation between sterically hindered racemic tertiary α-allenyl alcohols and tetrasubstituted silyl ketene acetals to provide β-allenyl ester products in good yield and with excellent enantioselectivity.
M. Isomura, D. A. Petrone, E. M. Carreira, J. Am. Chem. Soc., 2021, 143, 3323-3329.
A gold-catalyzed reaction of sulfonium and selenium ylides with aryldiazoacetates provides products of a [2,3]-sigmatropic rearrangement in high yields. A reaction of aryl allyl anilines delivers exclusively C-H functionalized products.
F. He, S. Jana, R. M. Koenigs, J. Org. Chem., 2020, 85, 11882-11891.