Diastereo- and Enantioselective Synthesis of Bisbenzannulated Spiroketals and Spiroaminals by Ir/Ag/Acid Ternary Catalysis.
Diastereo- and Enantioselective Synthesis of Bisbenzannulated Spiroketals and Spiroaminals by Ir/Ag/Acid Ternary Catalysis.
复制标题
通过 Ir/Ag/酸三元催化非对映和对映选择性合成双苯环化螺缩酮和螺胺醛。
作者：
Wulin Yang;Xinghong Shang;Tao Ni;Hui Yan;Xiaoyan Luo;Hanliang Zheng;Z. Li;W. Deng
本文报道了一种高效率地合成双苯并[6，6]螺酮的Ir/银/酸三元催化体系，具有很高的非对映选择性和对映体选择性(高达>；20：1dr，>；99%ee)。在这一过程中，容易获得的邻炔基苯乙酮经过环异构化反应生成异色烯，与2-(1-羟基烯丙基)酚参与立体选择性的烯丙化/螺酮化反应。同时，2-(1-羟基烯丙基)苯胺在级联反应中也是相容的，提供了结构新颖的双苯并[6，6]-螺胺类化合物，具有良好的非对映选择性(8：1-12：1dr)和良好的对映体选择性(98%-gt；99%ee)。此外，还进行了实验研究和理论计算，阐明了反应机理和立体化学。
We reported herein an iridium/silver/acid ternary catalytic system to access bisbenzannulated [6,6]-spiroketals in high efficiency with generally high diastereo- and enantioselectivities (up to >20:1 dr, >99% ee). In this procedure, readily available o -alkynylacetophenones undergo cycloisomerization to generate isochromenes in situ that participate in stereoselective allylation/spiroketalization sequence with 2-(1-hydroxyallyl)phenols. Meanwhile, 2-(1-hydroxyallyl)anilines were also compatible in this cascade reaction, furnishing structurally novel bisbenzannulated [6,6]-spiroaminals with good diastereoselectivities (8:1-12:1 dr) and excellent enantioselectivities (98%->99% ee). Moreover, experimental studies and theoretical calculations were performed to illustrate the reaction mechanism and stereochemistry.