42045-60-3Relevant articles and documents
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.
New Phenolic Components from Dalbergia Volubilis
Chawla, H. Mohindra,Johny, C. J.,Mittal, Ram S.
, p. 82 - 87 (2007/10/02)
Phytochemical examination of non green branches of Dalbergia volubilis on extensive column and preparative thin layer chromatography yielded twelve compounds eight of which are already known compounds and were identified as sitosterol, 7-hydroxy-4-methyl-coumarin, dalbergin, biochanin-A, umbelliferone, p-hydroxy cinnamic acid, kaempferol and quercetin-3-O-glucoside.The other four compounds were new natural products, three of which were identified as novel 4-phenyl-2H-1-benzopyran-2-ones while the fourth one was a new 12a-hydroxy rotenoid.The structure of these new compounds has been established on the basis of chemical and spectral evidences and through derivatization, as 4',7-dihydroxy-3'-methoxy-4-phenyl-2H-1-benzopyran-2-one, 3',7-dihydroxy-4',5-dimethoxy-2H-1-benzopyran-2-one, 3',7-dihydroxy4',5-dimethoxy-6-formyl-2H-1-benzopyran-2-one and a complex rotenoid determined to be as (VII).The co-occurence of 4-methyl-2H-1-benzopyran-2-ones, 4-phenyl-2H-1-benzopyran-2-ones, isoflavones and rotenoids is of interest from biogenetic considerations.
VOLUBOLIN, A 4-PHENYL-2H-1-BENZOPYRAN-2ONE FROM DALBERGIA VOLUBILIS
Chawla, H. Mohindra,Mittal, Ram S.
, p. 2625 - 2626 (2007/10/02)
From the ether soluble portion of a methanolic extract of young non-green branches of Dalbergia volubilis, sitosterol, 7-hydroxy-4-methyl-2H-1-benzopyran-2-one, dalbergin, p-hydroxy cinnamic acid, biochanin-A and a new 4-phenylcoumarin, volubolin, have been isolated.The structure of volubolin as 7-hydroxy-4-(3-hydroxy-4-methoxy-phenyl)-2H-1-benzopyran-2-one has been established on the basis of spectral and chemical evidence.Cooccurrence of 4-methyl- and 4-phenyl-coumarins with isoflavones is of biogenetic interest. - Key Word Index: Dalbergia volubilis; Leguminosae; young branches; 7-hydroxy-4-methyl coumarin; dalbergin; biochanin-A; 7-hydroxy-4-(3-hydroxy-4-methoxyphenyl)-2H-1-benzopyran-2-one.
