An Asymmetric Synthesis of <i>trans</i>-Fused Butyrolactones from Endoperoxides

The intermolecular addition of 1,3-dicarbonyl equivalents to endoperoxides in the presence of an organocatalyst yields <i>trans</i>-fused butyrolactones in high yield and enantioselectivities. This methodology expands the synthetic utility of endoperoxides and further underlines their potential as sources of oxygen functionality for natural and non-natural product target synthesis

Photoredox Approach to <i>N</i>‑Acyl-<i>N′</i>-aryl‑<i>N</i>,<i>N′</i>-aminals Using Enamides and Their Conversion to γ‑Lactams

A photoredox catalytic approach to synthetically valuable <i>N</i>-acyl-<i>N</i>′-aryl-<i>N</i>,<i>N</i>′-aminals is described. This method uses the addition of a radical precursor to enamides, with subsequent interception of the cationic iminium intermediate with an arylamine. The reaction has been shown to be compatible with electron-rich and electron-deficient arylamines, and moderate to good levels of diastereoselectivity can be attained using a chiral enamide. Furthermore, the <i>N</i>-acyl-<i>N</i>′-aryl-<i>N</i>,<i>N</i>′-aminal reaction products can be readily cyclized, providing a novel synthetic route to valuable γ-lactams

The Au(I) Catalyzed Activation of Allenamides and Their Subsequent Transformation into Chromanes: A Method for the Regiocontrolled Addition to the α- and γ‑Positions of the Allene Unit

Au­(I) activation of allenamides in the presence of phenols leads to the formation of chromanes in moderate to good yields. This catalytic process is dependent on the counterion which facilitates the activation of the <i>in situ</i> formed imine. Furthermore, this iminium can be intercepted by trimethylallyl silane, via the Hosomi–Sakurai reaction, giving a formal procedure for the regioselective intermolecular addition of two carbon nucleophiles to an allenamide at the α- and γ-positions

Controlling the Assembly of C2-Symmetric Molecular Tectons Using a Thiocarbamate Appended Carbocyclic Cleft Molecule Analogous to Tröger’s Base

By way of appending the C₂-symmetric carbocyclic cleft diol with thiocarbamates with varying substituents, significant control of the hydrogen bonded network can be achieved. Smaller alkyl substituents lead to the formation of stacked columns of components with the apex of one molecule suitably aligned in the cleft of a second. Aryl substituents, however, lead to the formation of ribbons via an H-bonding network. Additionally, the packing of these ribbons into networks is considerably different between the enantiopure and racemic clefts, with the latter giving rise to channels within the crystal structure

Synthesis of Mono‑<i>O</i>‑alkylated Homo­oxa­calix­[3]­arene and a Protection–Deprotection Strategy for Homo­oxa­calix­[3]­arene

The regioselective synthesis of mono-<i>O</i>-alkylated homo­oxacalix­[3]­arene is accomplished for the first time. The synthetic route relies on two key steps: (i) a facile protection of two OH groups at the lower rim of the homo­oxacalix­[3]­arene and (ii) the deprotection of 9-anthrylmethyl groups via the Pd/C-catalyzed hydrogenation under atmospheric hydrogen. An efficient protection–deprotection strategy for the functionalization of homo­oxacalix­[3]­arene is presented

Synthesis of Mono‑<i>O</i>‑alkylated Homo­oxa­calix­[3]­arene and a Protection–Deprotection Strategy for Homo­oxa­calix­[3]­arene

The regioselective synthesis of mono-<i>O</i>-alkylated homo­oxacalix­[3]­arene is accomplished for the first time. The synthetic route relies on two key steps: (i) a facile protection of two OH groups at the lower rim of the homo­oxacalix­[3]­arene and (ii) the deprotection of 9-anthrylmethyl groups via the Pd/C-catalyzed hydrogenation under atmospheric hydrogen. An efficient protection–deprotection strategy for the functionalization of homo­oxacalix­[3]­arene is presented

Blue-Emitting Butterfly-Shaped 1,3,5,9-Tetraarylpyrenes: Synthesis, Crystal Structures, and Photophysical Properties

The first example of aryl-functionalized, butterfly-shaped, highly fluorescent and stable blue-emitting monomers, namely, 7-<i>tert</i>-butyl-1,3,5,9-tetrakis(<i>p</i>-R-phenyl)pyrenes, were synthesized by the Suzuki–Miyaura cross-coupling reaction from a novel bromide precursor of 1,3,5,9-tetrabromo-7-<i>tert</i>-butylpyrene. The crystal structures and optical and electronic properties have been investigated

An Efficient Approach to the Synthesis of Novel Pyrene-Fused Azaacenes

An efficient synthetic approach for functionalization of both the active sites (1,3-) and the K-region (4,5,9,10-) of pyrene was accomplished by bromination and oxidation with considerable yield. These novel pyrene-fused azaacenes were thoroughly investigated by X-ray diffraction studies, electrochemistry, and DFT calculations

Regio- and Stereoselective Polymerization of Diynes with Inorganic Comonomer: A Facile Strategy to Conjugated Poly(<i>p</i>‑arylene dihalodiene)s with Processability and Postfunctionalizability

Development of new methodologies for synthesizing polymers with novel structures and unique properties is a fundamentally important area in polymer science. Herein, a novel synthetic strategy to conjugated poly­(<i>p</i>-arylene dihalodiene)­s (PADs) with high regio- and stereoselectivity was developed. In the presence of PdBr₂ and CuBr₂, the polymerizations of terminal alkynes proceeded smoothly in air without heating to generate PADs in high yields (up to 95.3%) with high molecular weights (<i>M</i>_w up to 915 900). Low-cost inorganic CuBr₂ played dual roles as cocatalyst and comonomer. The PADs possessed good solubility and film-forming ability. Their thin films exhibited high refractive indices (1.7149–1.7245) and would be fabricated into well-resolved fluorescent photopatterns by photolithography. Thanks to the vinyl bromine functionality, the PADs could undergo efficient postmodification to afford polymers with more sophisticated structures and applications

Synthesis and characterization of new tetraalkylaminophosphonium chlorides

<p>New tetraalkylaminophosphonium chlorides were readily prepared by four-fold condensation of commercially available [P(CH₂OH)₄]Cl with a range of fifteen aryl based primary amines, in EtOH, at ambient temperature. All compounds have been characterized by FT–IR spectroscopy and elemental analysis. Solution ³¹P{¹H} NMR studies of these chloride salts reveal their instability with respect to various P^III/P^V species. The structures of three examples have been determined by single crystal X-ray diffraction and confirm the pseudotetrahedral arrangement around the P^V center. Extensive N–H···Cl hydrogen bonding is observed.</p