Catalytic asymmetric conjugate addition of various α-mercaptoketones to α,β-unsaturated N-acylated oxazolidin-2-ones with bifunctional organocatalyst
作者:Bo-Liang Zhao、Da-Ming Du
DOI:10.1039/c4ra02400a
日期:——
catalysed enantioselectiveconjugateMichaeladdition reaction of various α-mercaptoketones to α,β-unsaturatedN-acylated oxazolidinones under mild reaction conditions has been developed. This catalytic reaction afforded the corresponding adducts in good yields with high enantioselectivities (up to 92% ee). This is the first example of organocatalysed sulfa-Michael addition using various α-mercaptoketones
Highly Efficient Asymmetric Michael Addition of Diaryl Phosphine Oxides to α,β-Unsaturated N-Acylated Oxazolidin-2-ones
作者:Depeng Zhao、Linqing Wang、Dongxu Yang、Yixin Zhang、Rui Wang
DOI:10.1002/asia.201200025
日期:2012.5
A highlyefficientasymmetricMichael reaction of diarylphosphineoxides with α,β‐unsaturated N‐acylated oxazolidinones has been developed. Excellent enantioselectivities (up to >99 % ee) and chemical yields (up to 99 %) were achieved with a broad substrate scope of the oxazolidinones. The bidentate property of oxazolidinones was found to be critical for high enantioselectivities.
The Catalytic Asymmetric Diels-Alder Reactions and Post-cycloaddition Reductive Transpositions of 1-Hydrazinodienes
作者:Hao Xie、Glenn M. Sammis、Eric M. Flamme、Christina M. Kraml、Erik J. Sorensen
DOI:10.1002/chem.201102394
日期:2011.9.26
Cycling through: Type I cyclohexenes are produced with high margins of stereoselectivity by chiral, catalyst‐controlled, Diels–Alderreactions between 1‐hydrazinodienes and N‐acryloyl oxazolidinone dienophiles, and readily transformed to cyclohexenes III via a putative, transient allylic diazene II (see scheme). This chemistry gives access to functionalized cyclohexenes that can be difficult to construct
Asymmetric β-Boration of α,β-Unsaturated <i>N</i>-Acyloxazolidinones by [2.2]Paracyclophane-Based Bifunctional Catalyst
作者:Lei Zhao、Yudao Ma、Wenzeng Duan、Fuyan He、Jianqiang Chen、Chun Song
DOI:10.1021/ol302839d
日期:2012.11.16
An efficient copper-catalyzed asymmetric conjugate boration has been achieved by exploiting a new planar and central chiral bicyclic triazolium ligand. This protocol was highly efficient and gave a variety of chiral secondary alkylboronates in 97-99% ee. A preliminary mechanistic study supports the bifunctional nature of the catalyst.