Trevor J. Rook

A novel, solution-processable non-fullerene electron acceptor, 6,6′-((9-(heptadecan-9-yl)-9H-carbazole-2,7-diyl)bis(thiophene-5,2-diyl))bis(2,5-bis(2-ethylhexyl)-3-(thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione) (coded as N7), based on central carbazole and terminal diketopyrrolopyrrole building blocks was designed, synthesized and characterized. N7 displayed excellent solubility, thanks to its design allowing incorporation of numerous lipophilic chains, thermal stability, and afforded a 2.30% power conversion efficiency with a high open-circuit voltage (1.17 V) when tested with the conventional donor polymer poly(3-hexylthiophene) in solution-processable bulk-heterojunction devices. To our knowledge, not only is N7 the first reported chromophore based on carbazole and diketopyrrolopyrrole functionalities but the open-circuit voltage reported here is among the highest values for a single junction bulk-heterojunction device that has been fabricated using a simple device architecture, with reproducible outcomes and with no special treatment.

The synthesis and olfactory properties of a series of 2‐substituted and 2,3‐annulated 1,4‐dioxepan‐6‐ones is reported. By Williamson etherification with 3‐chloro‐2‐(chloromethyl)prop‐1‐ene (6) and subsequent Katsuki–Sharpless oxidation, 1,4‐dioxepan‐6‐one (8 a) and its 2‐methyl (8 b), 2‐propyl (8 c), 2‐isobutyl (8 d), and 2,2,3,3‐tetramethyl derivative (8 e), as well as four 2,3‐annulated 1,4‐dioxepan‐6‐ones 8 h, 8 i, 8 j, and 8 k were synthesised. By etherification with ethyl diazoacetate and subsequent Dieckmann cyclisation, (5aS,9aS)‐9‐bromo‐ and 9‐iodo‐5a,6,7,9a‐tetrahydro‐2 H‐benzo[b][1,4]dioxepin‐3(4 H)‐one (8 f/g) as well as a 2,3‐annulated derivative 8 m from (+)‐limonene were prepared. 2‐Propyl‐1,4‐dioxepan‐6‐one (8 c) was discovered to have a green floral odour with anisic and cinnamic nuances, which could be rationalised by a superposition analysis. The olfactory properties of the 1,4‐dioxepan‐6‐ones synthesised underline the crucial importance of a benzenoid ring system for marine odorants.

Various 5-methyl-3-aminofurans have been shown to undergo facile Diels–Alder reactions with methyl acrylate in aqueous media. Reactions proceeded with exclusive regiochemistry, and enamine cycloadducts were readily hydrolyzed to afford 7-oxabicyclo[2.2.1]heptanones in high yields.

Salvinorin A 1, a psychoactive neoclerodane diterpenoid from the Mexican sage S. divinorum, has gained interest as a selective ?-opioid receptor agonist. Non-racemic 3-furylamines 9a and 9b have been prepared from (+)-pseudoephedrine and (–)-ephedrine for application in the stereoselective synthesis of the ketone ring of 1. Diels–Alder reaction of 9b with methyl acrylate in aqueous media, followed by selective ether bridge cleavage, has allowed access to the cyclohexenone 17 with preservation of stereochemistry at C2. A model route to the lactone ring has also been achieved through a one-pot deconjugation/esterification procedure of 2-bromocrotonyl chloride 20 to the furyl alcohol 19 followed by Reformatski-mediated ring closure.

Highly filled polypropylene (PP) composites have been produced by extrusion of polypropylenes with surface treated fillers. The aim is to include the highest proportion of filler that can provide hardness and high density, without undue brittleness. Modification of the filler surface provided significant enhancement of the processing properties that have been studied with parallel plate rheometry. The experimental results indicated that the viscoelastic behavior of melt flow of highly filled polypropylene composites significantly depended on the following properties of the fillers: aspect ratio, specific surface area and particle size in talc, calcium carbonate and barium sulfate filled polypropylene composites. Traditional surface modifiers such as stearic acid are useful, but titanates and in particular small amounts of silicones have provided the greatest rheological modification.

A general and efficient method for the synthesis of 3-furylamines via Michael addition of amines to acyclic keto alkynol precursors has been achieved. The preparation of various 3-furylamines has been carried out using a flexible methodology which also allows modification of the substituent at the 5-position.

Highly filled polypropylene composites have been prepared with filler contents up to 43.8 vol.% (70 wt.%) after surface treatment of the fillers with titanate or silicone. The fillers used were calcium carbonate, talc and barium sulfate. Surface modification of the fillers facilitated extrusion and reduced brittleness while providing hard composites with high density. The high density and hardness provide a texture which is not characteristic of polypropylenes, but more like thermoset composites or ceramics; yet the composites can be extruded using typical thermoplastic processing equipment. The composition has been measured by thermogravimetry, and morphology observed with scanning electron microscopy. The tensile properties were measured and related to the composition, filler type and surface treatment.