99515-51-2Relevant academic research and scientific papers
Integrating Metal-Catalyzed C-H and C-O Functionalization to Achieve Sterically Controlled Regioselectivity in Arene Acylation
Serratore, Nicholas A.,Anderson, Constance B.,Frost, Grant B.,Hoang, Truong-Giang,Underwood, Steven J.,Gemmel, Philipp M.,Hardy, Melissa A.,Douglas, Christopher J.
supporting information, p. 10025 - 10033 (2018/07/21)
One major goal of organometallic chemists is the direct functionalization of the bonds most recurrent in organic molecules: C-H, C-C, C-O, and C-N. An even grander challenge is C-C bond formation when both precursors are of this category. Parallel to this is the synthetic goal of achieving reaction selectivity that contrasts with conventional methods. Electrophilic aromatic substitution (EAS) via Friedel-Crafts acylation is the most renowned method for the synthesis of aryl ketones, a common structural motif of many pharmaceuticals, agrochemicals, fragrances, dyes, and other commodity chemicals. However, an EAS synthetic strategy is only effective if the desired site for acylation is in accordance with the electronic-controlled regioselectivity of the reaction. Herein we report steric-controlled regioselective arene acylation with salicylate esters via iridium catalysis to access distinctly substituted benzophenones. Experimental and computational data indicate a unique reaction mechanism that integrates C-O activation and C-H activation with a single iridium catalyst without an exogenous oxidant or base. We disclose an extensive exploration of the synthetic scope of both the arene and the ester components, culminating in the concise synthesis of the potent anticancer agent hydroxyphenstatin.
A photoredox-neutral Smiles rearrangement of 2-aryloxybenzoic acids
Gonzalez-Gomez, Jose C.,Ramirez, Nieves P.,Lana-Villarreal, Teresa,Bonete, Pedro
, p. 9680 - 9684 (2017/11/30)
We report on the use of visible light photoredox catalysis for the radical Smiles rearrangement of 2-aryloxybenzoic acids to obtain aryl salicylates. The method is free of noble metals and operationally simple and the reaction can be run under mild batch or flow conditions. Being a redox neutral process, no stoichiometric oxidants or reductants are needed.
Efficient Aryl Migration from an Aryl Ether to a Carboxylic Acid Group To Form an Ester by Visible-Light Photoredox Catalysis
Wang, Shao-Feng,Cao, Xiao-Ping,Li, Yang
supporting information, p. 13809 - 13813 (2017/10/24)
We have developed a highly efficient aryl migration from an aryl ether to a carboxylic acid group through retro-Smiles rearrangement by visible-light photoredox catalysis at ambient temperature. Transition metals and a stoichiometric oxidant and base are avoided in the transformation. Inspired by the high efficiency of this transformation and the fundamental importance of C?O bond cleavage, we developed a novel approach to the C?O cleavage of a biaryl ether to form two phenolic compounds, as demonstrated by a one-pot, two-step gram-scale reaction under mild conditions. The aryl migration exhibits broad scope and can be applied to the synthesis of pharmaceutical compounds, such as guacetisal. Primary mechanistic studies indicate that the catalytic cycle occurs by a reductive quenching pathway.
Quinclidine derivatives as squalene synthase inhibitors
-
, (2008/06/13)
Quinuclidine derivatives of formula, and their pharmaceutically acceptable salts, in which: R1 is hydrogen or hydroxy; R2 is hydrogen; pr R1 and R2 are joined together so that CR1 -CR2 is a
