WingPhos, a C2‐symmetric bisphosphorus ligand with a deep and well‐defined chiral pocket was developed. It has shown high efficiency in the rhodium‐catalyzed asymmetrichydrogenation of (E)‐β‐aryl‐N‐acetyl enamides, cyclic β‐aryl enamides, and heterocyclic β‐aryl enamides. A series of chiral β‐arylisopropylamines, 2‐aminotetralines, and 3‐aminochromans can be synthesized with excellent ee values (nbd=3
WingPhos是一种C 2对称的双磷配体,具有较深且定义明确的手性口袋。在(E)-β-芳基-N-乙酰基酰胺,环状β-芳基酰胺和杂环β-芳基酰胺的铑催化不对称氢化反应中显示出很高的效率。可以合成一系列具有良好ee值(nbd = 3,5-降冰片二烯; TON =周转数)的手性β-芳基异丙胺,2-氨基四氢呋喃和3-氨基苯并二氢吡喃。
A Versatile Synthesis of Vinyl-Substituted Heterocycles via Regio- and Enantioselective Pd-Catalyzed Tandem Allylic Substitution
作者:Chao Qian、Wenjun Tang
DOI:10.1021/acs.orglett.0c01490
日期:2020.6.5
We herein report a versatile, regio- and enantioselective palladium-catalyzed tandem allylicsubstitution powered by a chiral bisphosphorus ligand WingPhos with the palladium loading as low as 0.1 mol %, forming a series of chiral vinyl-substituted heterocycles, including tetrahydroquinoxalines, piperazines, dihydro-2H-benzo[b][1,4]-oxazines, and morpholines, in exellent ee’s and yields. The protocol
我们在本文中报道了一种手性双磷配体WingPhos驱动的多功能,区域和对映体选择性的钯催化串联烯丙基取代,钯载量低至0.1 mol%,形成了一系列手性乙烯基取代的杂环,包括四氢喹喔啉,哌嗪,二氢-2 H-苯并[ b ] [1,4]-恶嗪和吗啉的优异ee和收率。该方案具有易于获得的起始原料,温和的反应条件和广泛的底物范围。机制研究支持串联烯丙基取代过程。