A remarkable rate acceleration of the Baylis–Hillman reaction

Abstract

Treatment of alpha-naphthyl acrylate with both aliphatic and aromatic aldehydes in the presence of DABCO (30 mol%) afforded the desired (alpha-methylene-beta-hydroxy)esters with reasonable chemical yields (51-88%) within 20 min.

Light-Triggered Catalytic Asymmetric Allylic Benzylation with Photogenerated C-Nucleophiles

“…The MBH carbonates 2a–e were synthesized as described in the literature. , The MBH carbonates 2f–k were synthesized as follows: to a mixture of the corresponding aromatic aldehyde (5 mmol, 1 equiv) and the naphthyl acrylate (1.2 equiv) was added DABCO (1 equiv) and stirred for 45 min at room temperature. For liquid aldehydes, the reaction was performed in neat conditions, whereas 1 mL of MeCN was used as solvent for solid aldehydes, after which the mixture was diluted with CH 2 Cl 2 (2 mL) and directly purified by silica gel column chromatography to furnish the corresponding MBH alcohol.…”

Reactions of Aldehydes and Ketones and their Derivatives

“…Using alkyl, fluoroalkyl, and benzyl acrylates in an attempt to stabilize the enolate intermediate, reasonable yields took days, or even weeks. 112 Phenyl and β-naphthyl acrylates were somewhat faster, but α-naphthyl (44) gave (45, R = Ph) in 88% yield in 20 min. Further exploration of (44) with other aldehydes showed a significant by-product (46) for R = Me, Et, and C 6 H 4 -4-NO 2 .…”

Morita–Baylis–Hillman reaction of acrylamide with isatin derivatives

“…In an effort to address the slow reaction rate of acrylamide, Hu et al [ 13 ] used dioxane/water in a 1:1 ratio, while Aggarwal et al [ 14 ] used quinuclidine in methanol to carry out the MBH reaction of acrylamide. Connon et al [ 15 ] utilized phenol and/or a H 2 O/ t -BuOH 7:3 system for rate acceleration and Guo et al used aryl activation [ 16 – 17 ]. Other reports made use of reactive aldehyde [ 18 ], post-MBH modifications [ 19 ], an organometallic approach [ 20 ] and other strategies [ 21 – 22 ].…”