Rhodium-Catalyzed Carbonylation of 3-Acyloxy-1,4-enynes for the Synthesis of Cyclopentenones

Functionalized cyclopentenones were synthesized by a Rh-catalyzed carbonylation of 3-acyloxy-1,4-enynes, derived from alkynes and α,β-unsaturated aldehydes. The reaction involved a Saucy–Marbet 1,3-acyloxy migration of propargyl esters and a [4 + 1] cycloaddition of the resulting acyloxy substituted vinylallene with CO

Rhodium-Catalyzed Stereoselective Intramolecular [5 + 2] Cycloaddition of 3‑Acyloxy 1,4-Enyne and Alkene

The first rhodium-catalyzed intramolecular [5 + 2] cycloaddition of 3-acyloxy 1,4-enyne and alkene was developed. The cycloaddition is highly diastereoselective in most cases. Various <i>cis</i>-fused bicyclo[5.3.0]­decadienes were prepared stereoselectively. The chirality in the propargylic ester starting materials could be transferred to the bicyclic products with high efficiency. Electron-deficient phosphine ligand greatly facilitated the cycloaddition. Up to three new stereogenic centers could be generated. The resulting diene in the products could be hydrolyzed to enones, which allowed the introduction of more functional groups to the seven-membered ring

Problem solving team interventions: Web-based and consultant-based experimental evaluations

This research was designed to develop, implement, and evaluate an assessment and intervention protocol to increase problem-solving teams' (PSTs) adoption and implementation of evidence-based practices aimed at students with disruptive behavior problems. Participants included 15 PSTs. Adopting single-case design methodology, we examined whether a customized set of assessment and intervention consultant-led intervention procedures could be used to improve the activities, process, and recommendations of PSTs compared to a web-based intervention. We were interested in evaluating two variations of the problem-solving model based on the team initiated problem-solving (TIPS) approach. TIPS includes steps to successful problem solving and solution implementation for student academic and behavioral concerns. Based on visual analysis and statistical randomization tests, we found that a teleconsultation web-based model of PST intervention was not effective in improving the functioning of the PST. In contrast, a customized, consultation-led intervention model with PST facilitators that followed this approach was found to be effective in improving both the foundation and thoroughness of the PST's problem solving. Implications of future PST improvement models for practice and research are discussed.Institute of Education Sciences24 month embargo; first published 11 January 2024This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Rhodium-Catalyzed Intra- and Intermolecular [5 + 2] Cycloaddition of 3-Acyloxy-1,4-enyne and Alkyne with Concomitant 1,2-Acyloxy Migration

A new type of rhodium-catalyzed [5 + 2] cycloaddition was developed for the synthesis of seven-membered rings with diverse functionalities. The ring formation was accompanied by a 1,2-acyloxy migration event. The five- and two-carbon components of the cycloaddition are 3-acyloxy-1,4-enynes (ACEs) and alkynes, respectively. Cationic rhodium­(I) catalysts worked most efficiently for the intramolecular cycloaddition, while only neutral rhodium­(I) complexes could facilitate the intermolecular reaction. In both cases, electron-poor phosphite or phosphine ligands often improved the efficiency of the cycloadditions. The scope of ACEs and alkynes was investigated in both the intra- and intermolecular reactions. The resulting seven-membered-ring products have three double bonds that could be selectively functionalized