Catalytic Asymmetric Alkynylation of C1-Substituted C,N-Cyclic Azomethine Imines by CuI/Chiral Brønsted Acid Co-Catalyst
作者:Takuya Hashimoto、Masato Omote、Keiji Maruoka
DOI:10.1002/anie.201104017
日期:2011.9.12
up: The title reaction was developed for the synthesis of chiral tetrahydroisoquinoline derivatives with a tetrasubstituted carbon center at the C1‐position (see scheme, Bz=benzoyl, pybox=2,6‐bis(2‐oxazolinyl)pyridine). The reaction was facilitated effectively by the co‐catalyst system composed of copper(I)/Ph‐pybox and an axiallychiraldicarboxylicacid.
Brønsted acid catalyzed [4 + 2] cycloaddition for the synthesis of bisbenzannulated spiroketals with antifungal activities
作者:Teng Hu、Yuxuan Zhao、Xiaoyan Luo、Zhong Li、Wu-Lin Yang
DOI:10.1039/d4ob00584h
日期:——
The intermolecular [4 + 2] cycloaddition of o-hydroxy benzyl alcohols with isochroman ketals was realized by CF3CO2H catalysis. A broad range of bisbenzannulated [6,6]-spiroketals were formed under the metal-free mild conditions in moderate to excellent yields (45–98%) with mostly excellent diastereoselectivities (up to >20 : 1 dr). Furthermore, the enantioselective version was also preliminarily investigated
通过CF 3 CO 2 H催化实现邻羟基苯甲醇与异色满缩酮的分子间[4+2]环加成反应。在无金属的温和条件下,形成了多种双苯环化[6,6]-螺缩酮,产率中等至优异(45-98%),并且具有优异的非对映选择性(高达>20:1 dr)。此外,还初步研究了对映选择性形式,在Sc(OTf) 3 /Feng的手性N , N '-二氧化物配体存在下,得到了双苯环化[6,6]-螺酮缩醛,其ee含量为61%。一些双苯环化[6,6]-螺缩酮产品对核盘菌和立枯丝核菌表现出良好的体外抗真菌活性。