新型轴向手性联苯二膦配体E n m -BridgePhos,在联苯主链的5,5′-位上带有醚链桥,已被开发并成功应用于Rh催化的α-acetamido-1的对映选择性不对称氢化反应,3-茚满二酮,以高产率(高达 97%)提供手性 α-乙酰氨基-β-羟基苯并环戊酮,并具有优异的对映选择性(高达 99% ee)。该反应可以在克级规模上进行,相应的产物可作为合成手性螺苄基异喹啉生物碱类似物的重要中间体。晶体结构分析和DFT计算均表明E nm -BridgePhos-Rh配合物的大二面角与优异的对映选择性密切相关。
Ru(II)-Catalyzed C–H Activation and Alkyne Annulation Reaction of Phenyl Indandiones: Synthesis of Spirobi[indene]diones
作者:Sanjib Gogoi、Bidisha R. Bora、Sabera Sultana、Bipul Sarma
DOI:10.1055/a-1743-0191
日期:2022.6
A Ru(II)-catalyzed synthesis of spirobi[indene]dione from phenyl indandione and alkyne is reported. This metal-catalyzed cyclization reaction proceeds through hydroxy group directed C(sp2)–H bond activation, keto–enol tautomerization and alkyneannulation pathways.
allowing selective access to tertiary alkylated ketones and alkenes. The present approach features commercially available starting materials, broad substrate scope, general functional-group (including halogen, ester, nitrile, thioether) tolerance. Furthermore, we proposed plausible pathways to rationalize the divergent selectivity through preliminary mechanism study.
direct insertion of alkenes into unstrained ring 2-aryl-1,3-indandiones is reported, which provides a one-carbon ring expansion strategy for the synthesis of 1,4-naphthoquinones. Entirely differing from the existing reports, the alkenes herein behave as C1 units to participate in annulation reactions. This transformation provides a facile route to access a class of highly functionalized 1,4-naphthoquinones
An intermolecular annulation reaction of 2‐aryl‐1,3‐indandions with alkynes was reported using Pd(OAc)2 to access spirobi[indene]‐1,3‐diones. Under palladium catalysis, the substrates form a homocoupling dimer intermediate through a catalytic dehydrogenativecross‐coupling process. The palladium(II) species could come from dimer or 2‐aryl‐1,3‐indandion. Notably, this pathway is not typically observed
据报道,使用 Pd(OAc)2 进行 2-芳基-1,3-茚满二酮与炔烃的分子间成环反应,得到螺二[茚]-1,3-二酮。在钯催化下,底物通过催化脱氢交叉偶联过程形成同偶联二聚体中间体。钯 (II) 物质可能来自二聚体或 2-芳基-1,3-茚满二酮。值得注意的是,这种途径通常在烯醇导向的形式 sp3 C-H 官能化/氧化成环钯化学中观察不到。这种转化提供了获得一类官能化螺环碳环茚的途径。