Chiral Ion-Pair Organocatalyst-Promoted Efficient Enantio-selective Reduction of α-Hydroxy Ketones
作者:Yiliang Zhang、Li He、Lei Shi
DOI:10.1002/adsc.201800053
日期:2018.5.16
The enantioselective reduction of α‐hydroxy ketones with catecholborane has been developed employing 5 mol% of an 1,1′‐bi‐2‐naphthol (BINOL)‐derived ion‐pair organocatalyst. This methodology provides a straightforwardaccess to the corresponding aromatic 1,2‐diols in high yields (up to 90%) with excellent enantioselectivities (up to 97%). Furthermore, the α‐amino ketones also could be reduced with
Vinylethylene Carbonates as <i>α,β</i>-Unsaturated Aldehyde Surrogates for Regioselective [3 + 3] Cycloaddition
作者:Yi Xu、Lu Chen、Yu-wen Yang、Zhiqiang Zhang、Weibo Yang
DOI:10.1021/acs.orglett.9b02266
日期:2019.9.6
operationally simple [3 + 3] cycloaddition of vinylethylene carbonates with triazinanes. Interestingly, we could also use this method for a [3 + 3] oxidative cycloaddition, which allows the facile synthesis of polysubstituted terphenyls under mild conditions. Mechanistic studies suggest that vinylethylene carbonates could generate α,β-unsaturatedaldehydes as 3-carbon synthons for cycloaddition via a combination
Ball-milling synthesized hydrotalcite supported Cu–Mn mixed oxide under solvent-free conditions: an active catalyst for aerobic oxidative synthesis of 2-acylbenzothiazoles and quinoxalines
Copper‐Catalyzed Enantioselective Construction of Tertiary Propargylic Sulfones
作者:José Enrique Gómez、Àlex Cristòfol、Arjan W. Kleij
DOI:10.1002/anie.201814242
日期:2019.3.18
asymmetric synthesis approach has been developed. We disclose a versatile copper‐catalyzed sulfonylation of propargylic cyclic carbonates using sodium sulfinates that allows the construction of propargylic sulfones featuring elusive quaternary stereocenters. This method provides the first successful example of such an enantioselective propargylic sulfonylation, features high asymmetric induction, wide functional
In this paper, we designed and synthesized a new type of cyclic carbonates, allenylethylene carbonates (AECs). With AECs as reactive precursors, we developed palladium-catalyzed (3+3) annulation of AECs with nitrile oxides. Various AECs worked well in this reaction under mild reaction conditions. A variety of 5,6-dihydro-1,4,2-dioxazine derivatives with allenyl quaternary stereocenters can be accessed