Novelroute for the construction of chromans from benzylic and aliphatic alcohols in the presence of NaHSO4/SiO2 has been developed. In this reaction, substituted olefins are formed from benzylic and aliphatic alcohols and then converted to chromans through intramolecular cyclization. Twenty novel chromans were synthesized by this simple procedure.
A formal [4 + 2] cycloaddition of N-tosylhydrazones with ortho-quinone methides was developed, affording the facile synthesis of diverse 1,3-oxazine derivatives under mild conditions. In this transformation, N-tosylhydrazones are used as a 1,2-dipole synthon under base-free conditions. Moreover, the substrate scope is broad, and the products are formed with high diastereoselectivities in most of the
Facile construction of functionalized 4H-chromene via tandem benzylation and cyclization
作者:Jinmin Fan、Zhiyong Wang
DOI:10.1039/b812046c
日期:——
A series of functionalized 4H-chromenes have been constructed by using a novel FeCl3-catalyzed benzylation–cyclization tandem reaction.
一系列官能化的4H-色烯化合物通过一种新型FeCl3催化的苄基化-环化串联反应构建而成。
Catalytic Asymmetric Conjugate Addition of Indoles to <i>para</i>-Quinone Methide Derivatives
作者:Jin-Rong Wang、Xiao-Li Jiang、Qing-Qing Hang、Shu Zhang、Guang-Jian Mei、Feng Shi
DOI:10.1021/acs.joc.9b00710
日期:2019.6.21
A catalyticasymmetric conjugate addition of indoles to o-hydroxyphenyl substituted p-quinone methides has been established in the presence of chiral phosphoric acid, which afforded chiral indole-containing triarylmethanes in generally high yields (54–98%) and good enantioselectivities (90:10–96:4 enantiomeric ratio). The control experiments indicated that o-hydroxyphenyl substituted p-quinone methides