Rate Acceleration of the Baylis−Hillman Reaction in Polar Solvents (Water and Formamide). Dominant Role of Hydrogen Bonding, Not Hydrophobic Effects, Is Implicated
作者:Varinder K. Aggarwal、David K. Dean、Andrea Mereu、Richard Williams
DOI:10.1021/jo016073y
日期:2002.1.1
A substantial acceleration of the Baylis-Hillmanreaction between cyclohexenone and benzaldehyde has been observed when the reaction is conducted in water. Several different amine catalysts were tested, and as with reactions conducted in the absence of solvent, 3-hydroxyquinuclidine was found to be the optimum catalyst in terms of rate. The reaction has been extended to other aldehyde electrophiles
Rhodium(II)-Catalyzed Reaction of 1-Tosyl-1,2,3-triazoles with Morita-Baylis-Hillman Adducts: Synthesis of 3,4-Fused Pyrroles
作者:Renmeng Jia、Jiang Meng、Jiaying Leng、Xingxin Yu、Wei-Ping Deng
DOI:10.1002/asia.201800057
日期:2018.9.4
A cascade reaction of rhodium azavinylcarbenes with Morita–Baylis–Hillman (MBH) adducts enables a novel synthetic approach to 3,4‐fused pyrroles. The cascade reaction begins with the insertion of O−H bond into rhodium azavinylcarbenes, subsquent sigmatropic rearrangement provides substituted α,β‐unsaturated cyclic ketone intermediates. Then the intramolecular aza Michael addition/oxidative aromatization
Superior amine catalysts for the Baylis–Hillman reaction: the use of DBU and its implications†
作者:Varinder K. Aggarwal、Andrea Mereu
DOI:10.1039/a907754e
日期:——
DBU, which is normally regarded as a hindered and non-nucleophilic base, is in fact the optimum catalyst for the BaylisâHillman reaction, providing adducts at much faster rates than using DABCO or 3HQD; the scope of the BaylisâHillman reaction is enhanced using this catalyst and implications of this finding are discussed.
The Baylis–Hillman reaction is shown to accelerate in salt solutions of water and the ‘water-like’ structured solvents, like formamide and N-methylformamide in the presence of DABCO. Ethylene glycol, another structured solvent and its salt solutions fail to make any impact on the reaction rates. The salts that are conventionally defined as salting-out or -in do not behave in a similar fashion, when