<em>N</em>,<em>N</em>-Dialkyl Amides as Versatile Synthons for Synthesis of Heterocycles and Acyclic Systems

N,N-Dialkyl amides such as N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), are common polar solvents, finds application as a multipurpose reagent in synthetic organic chemistry. They are cheap, readily available and versatile synthons that can be used in a variety of ways to generate different functional groups. In recent years, many publications showcasing, excellent and useful applications of N,N-dialkyl amides in amination (R-NMe2), formylation (R-CHO), as a single carbon source (R-C), methylene group (R-CH2), cyanation (R-CN), amidoalkylation (-R), aminocarbonylation (R-CONMe2), carbonylation (R-CO) and heterocycle synthesis appeared. This chapter highlights important developments in the employment of N,N-dialkyl amides in the synthesis of heterocycles and functionalization of acyclic systems. Although some review articles covered the application of DMF and/or DMA in organic functional group transformations, there is no specialized review on their application in the synthesis of cyclic and acyclic systems

C▬H Activation Strategies for Heterofunctionalization and Heterocyclization on Quinones: Application in the Synthesis of Bioactive Compounds

Quinone moieties in general and heterofunctionalized or heterofused quinones in particular find application in several fields such as medicinal chemistry, natural products, and functional materials. Due to its striking applications, scientists developed useful methods for the synthesis of quinone derivatives. C▬H activation strategy is a fast-developing and straightforward concept, used in the construction of a diverse variety of bonds such as carbon▬carbon (C▬C) and carbon▬hetero (C▬O/N/S/P) bonds and also used is the heterofunctionalization/heterocyclization of quinones. Such approaches are useful in making use of unfunctionalized quinones for the synthesis of heterofunctionalized or heterocycle-fused quinones. The redox active nature and ligand-like properties make it difficult to carryout C▬H activation on quinones. In this chapter we summarized recent developments on strategies used for C▬hetero atom bond formation on quinones via C▬H activation, leading to heterofunctionalization and synthesis of heterofused quinones

1-(Benz­yloxy)naphthalene

In the title compound, C17H14O, the dihedral angle between the naphthyl ring system and the benzyl group is 83.22 (4)°. Both of these moieties are planar, with mean deviations from their least-squares planes, defined by the naphthyl ring C atoms and the O atom, and the phenyl ring C atoms and the benzyl α-C atom, of 0.0176 (1) and 0.0024 (13) Å, respectively. The crystal structure is stabilized by C—H⋯π and π–π inter­actions [centroid–centroid distance = 3.7817 (10) Å]

Crystal structure, Hirshfeld surfaces and DFT computation of NLO active (2E)-2-(ethoxycarbonyl)-3-[(1-methoxy-1-oxo-3-phenylpropan-2-yl)amino] prop-2-enoic acid

Nonlinear optical (NLO) activity of the compound (2E)-2-(ethoxycarbonyl)-3-[(1-methoxy-l-oxo-3phenylpropan-2-yl)amino] prop-2-enoic add is investigated experimentally and theoretically using X-ray crystallography and quantum chemical calculations. The NLO activity is confirmed by both powder Second Harmonic Generation (SHG) experiment and first hyper polarizability calculation. The title compound displays 8 fold excess of SHG activity when compared with the standard compound KDP. The gas phase geometry optimization and vibrational frequencies calculations are performed using density functional theory (DFT) incorporated in B3LYP with 6-311G++ (d,p) basis set. The title compound crystallizes in non-centrosymmetric space group P21. Moreover, the crystal structure is primarily stabilized through intramolecular N-H center dot center dot center dot O and O-H center dot center dot center dot O hydrogen bonds and intermolecular C-H center dot center dot center dot O and C-H center dot center dot center dot pi interactions. These intermolecular interactions are analyzed and quantified using Hirshfeld surface analysis and PIXEL method. The detailed vibrational assignments are performed on the basis of the potential energy distributions (PED) of the vibrational modes. (C) 2015 Elsevier B.V. All rights reserved.Peer reviewe

A highly efficient green synthesis of 1, 8-dioxo-octahydroxanthenes

SmCl3 (20 mol%) has been used as an efficient catalyst for reaction between aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione at 120°C to give 1,8-dioxo-octahydroxanthene derivatives in high yield. The same reaction in water, at room temperature gave only the open chain analogue of 1,8-dioxo-octahydroxanthene. Use of eco-friendly green Lewis acid, readily available catalyst and easy isolation of the product makes this a convenient method for the synthesis of either of the products

Total synthesis of (+)-grandiamide D, dasyclamide and gigantamide A from a Baylis–Hillman adduct: A unified biomimetic approach

A unified strategy was followed for the synthesis of three putrescine bisamides, (+)-grandiamide D, dasyclamide and gigantamide A, isolated from leaves of Aglaia gigantea, by making use of a common synthetic intermediate prepared by the Baylis–Hillman reaction. Asymmetric synthesis of the natural (+)-grandiamide D was accomplished from camphor sultam

Direct Amidation of 2′-Aminoacetophenones Using I₂‑TBHP: A Unimolecular Domino Approach toward Isatin and Iodoisatin

Synthesis of isatin and iodoisatin from 2′-aminoacetophenone was achieved via oxidative amido cyclization of the sp³ C–H bond using I₂–TBHP as the catalytic system. The reaction proceeds through sequential iodination, Kornblum oxidation, and amidation in one pot. This method is simple, atom economic, and works under metal- and base-free conditions

Copper-Mediated Selective C–H Activation and Cross-Dehydrogenative C–N Coupling of 2′‑Aminoacetophenones

Isatins were obtained by cross-dehydrogenative C–N annulation and dealkylative C–N annulation of 2′-<i>N</i>-aryl/alkylaminoacetophenones and 2′-<i>N</i>,<i>N</i>-dialkylaminoacetophenones respectively in the presence of Cu(OAc)_<i>2</i>·H₂O/NaOAc/air. However, on reaction with CuBr, 2′-<i>N</i>-benzylaminoacetophenones underwent selective oxidation of an α-methylene group of amine rather than the 2-acetyl group to provide corresponding benzamides exclusively. Base played an important role in selective oxidation by lowering the temperature and time

γ‑Carbonyl Quinones: Radical Strategy for the Synthesis of Evelynin and Its Analogues by C–H Activation of Quinones Using Cyclopropanols

Cyclopropanols, on oxidative ring opening with AgNO₃–K₂S₂O₈ in DCM–H₂O at room temperature and under open flask conditions, produced β-keto radicals which were successfully added to quinones to furnish γ-carbonyl quinones. This mild method has been applied to the synthesis of cytotoxic natural products, 4,6-dimethoxy-2,5-quino­dihydro­chalcone and evelynin