Guanidine-Catalyzed γ-Selective Morita–Baylis–Hillman Reactions on α,γ-Dialkyl-Allenoates: Access to Densely Substituted Heterocycles
摘要:
N-Methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) was discovered as an excellent catalyst for the Morita-Baylis-Hillman reaction for previously hard-to-activate ,-dialkyl allenoate substrates. The obtained densely substituted allenic alcohols, which are generally inaccessible with other Lewis base catalysts, could be further converted into 2,5-dihydrofuran and 2H-pyran-2-one heterocyclic structures with challenging substitution patterns.
Diastereomerically Pure Morita–Baylis–Hillman (MBH) Acetates and Carbonates from Allenic α- and γ-MBH Alcohols
作者:Philipp Selig、Tai-Lam Nghiem
DOI:10.1055/s-0034-1380140
日期:——
Diastereomerically pure allenic Morita-Baylis-Hillman (MBH) acetates and carbonates have been prepared from their corresponding - and -MBH alcohols. Derivatizations proceeded under standard conditions without epimerization. Both - and -MBH derivatives were shown to be suitable substrates for further transformations.