Palladium catalysed queuing processes. Part 1: Termolecular cyclization–anion capture employing carbon monoxide as a relay switch and hydride, organotin(IV) or boron reagents
作者:Stephen Brown、Stephen Clarkson、Ronald Grigg、W.Anthony Thomas、Visuvanathar Sridharan、D.M Wilson
DOI:10.1016/s0040-4020(00)01103-0
日期:2001.2
enhance the scope of our cyclization–anion capture methodology, is introduced and exemplified by a wide variety of catalytic cyclization–carbonylation–anion capture processes employing hydride, organostannanes and NaBPh4 as anion capture agents. Mono- and bis-cyclization processes forming 5- and 6-membered rings are described, all of which employ CO at atmospheric pressure. Cyclocarboformylation processes
Palladium-Catalyzed Carbohalogenation: Bromide to Iodide Exchange and Domino Processes
作者:Stephen G. Newman、Jennifer K. Howell、Norman Nicolaus、Mark Lautens
DOI:10.1021/ja206099t
日期:2011.9.28
Aryl bromides have been used to prepare a variety of nitrogen- and oxygen-containing heterocycles featuring new carbon-carbon and carbon-iodine bonds. This palladium-catalyzed carbohalogenation requires potassium iodide for the reaction to proceed in high yields. Additionally, the first examples of domino carbohalogenation reactions have been demonstrated using both aryl iodide and aryl bromide starting materials. Complex products with multiple rings and stereogenic centers are generated in excellent yields with moderate to excellent diastereoselectivities.
Palladium catalysed tandem cyclisation-anion capture processes. Part 1. Background and hydride ion capture by alkyl- and π-allyl-palladium species.
A new, wide ranging, synthetically powerful, catalytic tandem cyclisation-anion capture process is proposed which depends on the rate of cyclisation of an organopalladium specifies (RPdX) onto a proximate alkene or diene being significantly faster than anion exchange and reductive elimination in the sequence RPdX → RPdY → RY + Pd(0). The catalytic cyclisation - anion capture sequence is illustrated
Palladium Catalysed Tandem Cyclisation–Anion Capture Processes. Part 4: Organotin(IV) Transfer Agents
作者:Paul Fretwell、Ronald Grigg、Jose M Sansano、Visuvanathar Sridharan、Sukanthini Sukirthalingam、David Wilson、James Redpath
DOI:10.1016/s0040-4020(00)00659-1
日期:2000.9
Palladium(0) catalysed cascade mono- and bis-cyclisation-anion capture involving a wide variety of starter species, terminating species and organotin(IV) anion capture reagents are reported leading to a range of bridged, fused and spirocyclic products. The diastereoselectivity of the bis-cyclisation processes is explained in terms of steric effects in the transition states. (C) 2000 Elsevier Science Ltd. All rights reserved.