Phosphite-mediated conversion of benzaldehydes into stilbenes via umpolung through a dioxaphospholane intermediate

AbstractThe phosphite-mediated coupling of two benzaldehydes into 2,2,2-triethoxy-1,3,2-dioxaphospholanes was investigated using 13C NMR spectroscopy and was found to be very sensitive to the nature of the ortho/para substituents, and promoted by electron-withdrawing groups (EWGs). Stilbene-extended tetrathiafulvalenes were prepared by heating the intermediate dioxaphospholane, containing aldehyde substituents at para positions and ethynyl groups at ortho/meta positions, with 1,3-dithiol-2-thiones in P(OEt)3. While EWGs promoted dioxaphospholane formation, electron-donating groups (EDGs), generated by conversion of the aldehydes into dithiafulvenes, promoted subsequent conversion into an alkene

Integrating sense of place in planning and management of multifunctional river landscapes: experiences from five European case studies

River landscapes are complex social-ecological systems with many benefts for people. A common challenge is to integrate social values in river planning and management. In particular, there is a paucity of research on the meaning and signifcance of place in river recreation and how people feel emotionally and spiritually connected to river landscapes. Based on fve European case studies, this study compares diferent methods and approaches for mapping sense of place in river landscapes and subsequently addresses the question of how these studies can inform participatory processes. The case studies are set in diverse geographical, institutional and policy contexts, including the planning and evaluation of river restoration projects in Switzerland, Denmark, Germany and Spain and the monitoring of the efects of newly constructed river dams in the Netherlands. This comparative study is a frst step in understanding the breadth of analytical and spatial approaches that can be used to assess sense of place in river landscapes and their implications for resilient river landscape planning and management