DOI: 10.1002/ejoc.201501423 Communication 1,2-Diones Copper-Assisted Synthesis of 2-Hydroxyphenyl-1,2-diones from Phenols and 2-Oxoaldehydes Narsaiah Battini, [a,b] Satyanarayana Battula, [a,b] and Qazi Naveed Ahmed* [a,b] Abstract: An efficient copper(II)-catalyzed protocol for the or- tho-functionalization of phenols was developed. A wide variety of 2-oxoaldehydes and phenols were tolerated, and the corre- Introduction Derivatives of benzils, such as 2-hydroxyphenyl-1,2-diones (HPDs), are widely distributed in nature. [1] These compounds possess intriguing structures and exhibit important biological activities such as anticancer, [1a,1b] antimicrobial, [1c] antioxid- ant, [1d] antibacterial, and hypertensive [1e] activities, and they also show inhibition of the enzymatic activity of carboxyl ester- ases [2] (Figure 1). As a result, the development of new practical methods for the synthesis of this scaffold is of considerable interest. In this context, Thasana and co-workers developed a method for the synthesis of HPDs through intramolecular cycli- zation of anionic benzylic esters of aryl benzyl ethers in the presence of a base followed by dioxirane oxidation. [3] This Scheme 1. Various synthetic approaches to 2-hydroxyphenyl-1,2-diones. [a] Medicinal Chemistry Division, Indian Institute of Integrative Medicine (IIIM/1871/2015), Jammu 180001, India E-mail: naqazi@iiim.ac.in http://www.iiim.res.in [b] Academy of Scientific and Innovative Research (AcSIR), 2-Rafi Marg, New Delhi, India Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/ejoc.201501423. Eur. J. Org. Chem. 2016, 658–662 © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 658 sponding 2-hydroxyphenyl-1,2-diones were afforded in appreci- able yields. Figure 1. Naturally occurring bioactive 2-hydroxyphenyl-1,2-diones. method, however, suffers with limitations in terms of using complex starting materials and the products are obtained in low yields. Li et al. reported the synthesis of HPDs by Fe II cata- lyzed ortho-functionalization of phenols with α-hydroxy ket- ones. [4] The yields were comparatively good, but longer reac- tion times and an external oxidant were required. Our group also established a synthetic strategy for the generation of HPDs through an amine-catalyzed cross-coupling approach. In this