Iron-catalysed Negishi coupling of benzylhalides and phosphates
作者:Robin B. Bedford、Michael Huwe、Mark C. Wilkinson
DOI:10.1039/b818961g
日期:——
Iron-based catalysts containing either 1,2-bis(diphenylphosphino)benzene or 1,3-bis(diphenylphosphino)propane give excellent activity and good selectivity in the Negishi coupling of aryl zinc reagents with a range of benzylhalides and phosphates.
Synthesis of Functionalized Diarylmethanes via a Copper-Catalyzed Cross-Coupling of Arylmagnesium Reagents with Benzylic Phosphates
作者:Christiane C. Kofink、Paul Knochel
DOI:10.1021/ol0616790
日期:2006.8.1
A combination of copper chloride, triethyl phosphite, and tetrabutylammonium iodide is a very efficient catalytic system for the synthesis of polyfunctionalized diarylmethanes, using the cross-coupling reaction of arylmagnesium halides with benzylic phosphates. The antibiotic Trimethoprim has been prepared using this Cu(I)-catalyzed cross-coupling in 52% overall yield (four steps).
Al(OTf)3 exhibits superior catalyst performance in the Friedel–Crafts‐type benzylation using benzylicphosphate as an electrophile. The reaction can be conducted even with 0.2 mol‐% of the catalyst. Twenty‐one different diarylmethanes are formed. The chemoselective property of the catalyst toward the phosphate group over acetate and bromide is noteworthy.
Benzylic Phosphates in Friedel–Crafts Reactions with Activated and Unactivated Arenes: Access to Polyarylated Alkanes
作者:Gangaram Pallikonda、Manab Chakravarty
DOI:10.1021/acs.joc.5b02441
日期:2016.3.4
Easily reachable electron-poor/rich primary and secondary benzylic phosphates are suitably used as substrates for Friedel–Craftsbenzylation reactions with only 1.2 equiv activated/deactivatedarenes (no additional solvent) to access structurally and electronically diverse polyarylated alkanes with excellent yields and selectivities at room temperature. Specifically, diversely substituted di/triarylmethanes
A variety of organophosphates are synthesized from n-BuLi-triggered, (additional) solvent-free reactions of diethyl phosphite with both activated/unactivated ketones and aldehydes preferably at room temperature via phospha-Brook rearrangement. We could successfully synthesize the naphthylic/allylic phosphates using this approach. (C) 2015 Elsevier Ltd. All rights reserved.