Pd-Catalyzed Selective B(6)–H Phosphorization of nido-Carboranes via Cascade Deboronation/B–H Activation from closo-Carboranes

Abstract

Efficient Pd-catalyzed regioselective B(6)−H phosphorization of nido-carboranes via cascade deboronation/B−H activation of readily available C-substituted o-carboranes with various phosphines using 3-methylpyridine or isoquinoline as a directing group in combination with pyridine ligands has been developed, affording unprecedented B(6)-phosphinated nidocarborane derivatives with high selectivity in a simple one-pot process.

Critical Discourse Analysis Based on Halliday’s Systemic Functional Linguistics: Taking The Economist’s First Commentation on the End of China’s Zero-COVID Policy as an Example

“…The selected news material Data, Diplomacy and Disease [4] was issued in The Economist on January 14, 2023. As per the reports on people.com [5] , the national key website, after the implementation of "Class B and B Management" for COVID-19 infection on January 8, 2023, the main responses for Chinese and foreign travelers were changed to optimize the travel management of Chinese and foreign travelers by ensuring COVID test for China-bound travelers within 48 hours before departure, canceling COVID-19 tests for all inbound travelers and centralized isolation, and canceling the number control measures for international passenger flights, such as "five ones" and passenger load factor restrictions. It was the first news commentation of The Economist about China's reopening policy in the era of COVID-19 following the termination of the strict restriction of "zero-COVID" on January 8, 2023.…”

Activation of Alkynes by a Redox-Active Carboranyl Diphosphine and Formation of Boron-Containing Phosphacycles

“…In contrast, the carborane B–H bonds are rather strong, with a bond dissociation energy estimated at 118 kcal/mol (comparable to aromatic C–H bonds). The chemistry of these boron vertices shares similarities with arene chemistry, and the functionalization usually proceeds through electrophilic substitution promoted by Lewis acids or by oxidative addition to electron-rich late transition metal centers. , Recently, the development of new transition metal-catalyzed coupling methods has significantly expanded the library of B-substituted carboranyl derivatives. − In addition to closo -{C 2 B 10 } cages, there has been a significant progress in the selective B-H bond functionalization for nido -{C 2 B 9 } clusters. , …”