Rhodium complex-catalyzed desilylative cyclocarbonylation of 1-aryl-2-(trimethylsilyl)acetylenes: a new route to 2,3-dihydro-1H-inden-1-ones
摘要:
Under water gas shift reaction conditions, 1-aryl-2-(trimethylsilyl)acetylenes undergo Rh-catalyzed desilylative cyclocarbonylation to give 2,3-dihydro-1H-inden-1-ones and trimethylsilanol. A wide variety of functional groups, such as methoxy, chloro, acetyl, ethoxycarbonyl, cyano, and trifluoromethyl, are tolerated on the aromatic ring under the reaction conditions. The products were obtained in good to excellent yield whether the substituent on the aromatic ring was electron-donating or electron-withdrawing. The cyclizations of substrates bearing a meta substituent on the aromatic ring regiospecifically gave 5-substituted-2,3-dihydro-1H-inden-1-ones except when the meta substituent was a methoxy group. The desilylative cyclocarbonylation is an alternative to the conventional preparation of 2,3-dihydro-1H-inden-1-ones, an intramolecular Friedel-Crafts acylation. A possible mechanism for the process is described.
Suzuki–Miyaura Coupling of Simple Ketones via Activation of Unstrained Carbon–Carbon Bonds
作者:Ying Xia、Jianchun Wang、Guangbin Dong
DOI:10.1021/jacs.8b02462
日期:2018.4.25
Here, we describe that simple ketones can be efficiently employed as electrophiles in Suzuki-Miyauracoupling reactions via catalytic activation of unstrained C-C bonds. A range of common ketones, such as cyclopentanones, acetophenones, acetone and 1-indanones, could be directly coupled with various arylboronates in high site-selectivity, which offers a distinct entry to more functionalized aromatic
在这里,我们描述了通过催化激活无张力的 CC 键,简单的酮可以在 Suzuki-Miyaura 偶联反应中有效地用作亲电子试剂。一系列常见的酮,如环戊酮、苯乙酮、丙酮和1-茚满酮,可以直接与各种芳基硼酸酯以高位点选择性偶联,这为获得更多功能化的芳香酮提供了独特的途径。初步机理研究表明酮 α-CC 键通过氧化加成断裂。
Two-Carbon Ring Expansion of 1-Indanones via Insertion of Ethylene into Carbon–Carbon Bonds
作者:Ying Xia、Shusuke Ochi、Guangbin Dong
DOI:10.1021/jacs.9b07445
日期:2019.8.21
A rhodium-catalyzed direct insertion of ethylene into a relatively unstrained carbon-carbon bond in 1-indanones is reported, which provides a two-carbon ring-expansion strategy for preparing seven-membered cyclic ketones. As many 1-indanones are commercially available and ethylene is inexpensive, this strategy simplifies synthesis of benzocycloheptenones that are valuable synthetic intermediates for
Intermolecular [5+2] Annulation between 1‐Indanones and Internal Alkynes by Rhodium‐Catalyzed C–C Activation
作者:Rui Zhang、Ying Xia、Guangbin Dong
DOI:10.1002/anie.202106007
日期:2021.9.6
Herein, we report a [5+2] cycloaddition between readily accessible 1-indanones and internal alkynes through Rh-catalyzed activation of less strained C−C bonds. The reaction is enabled by a strongly σ-donating NHC ligand and a carefully modified temporary directing group. A wide range of functional groups is tolerated, and the method provides straightforward access to diverse benzocycloheptenones that
Ditopic binding of various dinitrogen compounds to three bisporphyrin molecular tweezers with spacers of varying conformational rigidity, incorporating the planar enediyne (1), the helical stiff stilbene (2), or the semi-rigid glycoluril motif fused to the porphyrins (3), are compared. Binding constants Ka = 10⁴-10⁶ M(-1) reveal subtle differences between these tweezers, that are discussed in terms