9,9-Spirobifluorene, Dithieno[3,2-b:2′,3′-d]silole and Oligothiophene Twist Cruciforms for Hydrogen Generation from Water and the Synthesis of a Thiophene-Fused Barrelene

9,9-Spirobifluorene, Dithieno[3,2-b:2′,3′-d]silole and Oligothiophene Twist Cruciforms for Hydrogen Generation from Water and the Synthesis of a Thiophene-Fused Barrelene</p

Concise synthesis of moracin M using Appel mediated dehydration of a bioinspired endoperoxide

A synthesis of moracin M using Appel dehydration of a biomimetic inspired endoperoxide and subsequent late stage aromatization, is described. A key 1,3-diene, obtained from a base-free Suzuki-Miyaura coupling, can undergo biomimetic oxidation to its endoperoxide, followed by dehydration under Appel conditions and aromatization to give a benzofuran, with subsequent deprotection then providing moracin M in only 4-steps. Alternatively, this 1,3‑diene can undergo aromatization and subsequent deprotection providing a synthetic route to resveratrol. </p

Transition-metal-free continuous-flow synthesis of 2,5-diaryl furans: access to medicinal building blocks and optoelectronic materials

The direct transformation of 1,3-dienes into valuable 2,5-diarylfurans using transition-metal-free conditions is presented. By employing a simple oxidation─dehydration sequence on readily accessible 1,3-dienes, important 2,5-diarylfuran building blocks frequently used in medicinal and material chemistry are prepared. The oxidation step is realized using singlet oxygen, and the intermediate endoperoxide is dehydrated under metal-free conditions and at ambient temperature using the Appel reagent. Notably, this sequence can be streamlined into continuous flow, thereby eliminating the isolation of the intermediate, often unstable endoperoxide. This leads to a significant improvement in isolated yields (ca. 27% average increase) of the 2,5-diarylfurans while also increasing safety and reducing waste. Our transition-metal-free synthetic approach to 2,5-diarylfurans delivers several important furan building blocks used commonly in medicinal chemistry and as optoelectronic materials, including short-chain linearly conjugated furan oligomers. Consequently, we also complete a short study of the optical and electrochemical properties of a selection of these novel materials.</p