Tetrasulfonated 1,2‐Bis(diphenylphosphanyl)ethane as a Building Block for the Synthesis of Disulfonated Alkyldiphenylphosphanes

Abstract

International audienceno abstrac

Cleavage of Benzyl Phosphonium Salts as Efficient Bypass for the Synthesis of Disulfonated Alkyldiphenylphosphanes Bearing an Oleum‐Sensitive Alkyl Group

“…The global yields of these two steps (alkylation and cleavage) were 60 %, 54 %, and 51 % for disulfonated alkyldiphenylphosphanes 1, 2 and 3, respectively. Table 1 gathers the yields obtained for the synthesis of these three sulfonated phosphanes both in our previous work (DPPETS pathway) [8] and in this publication (BDPPTS pathway). The global yields obtained for the alkylation and cleavage steps are always higher for the BDPPTS pathway (factor 1.3, 1.2, and 1.3 for phosphanes 1, 2, and 3, respectively).…”

“…Thus, we recently described a new pathway from tetrasulfonated 1,2‐bis(diphenylphosphanyl)ethane (DPPETS) and an alkyl bromide. DPPETS was alkylated and then cleaved to produce the targeted phosphanes (Scheme a) . This strategy used the property of the quaternary bis(phosphonium) salts of DPPETS to be cleaved by lithium aluminium hydride (LiAlH 4 ) producing a disulfonated alkyldiphenylphosphane with loss of ethylene and H 2 .…”

“…DPPETS was alkylated and then cleaved to produce the targeted phosphanes (Scheme 1a). [8] This strat-egy used the property of the quaternary bis(phosphonium) salts of DPPETS to be cleaved by lithium aluminium hydride (LiAlH 4 ) producing a disulfonated alkyldiphenylphosphane with loss of ethylene and H 2 . However, the time for the synthesis of DPPETS by sulfonation of 1,2-bis(diphenylphosphanyl)ethane (DPPE) was long (14 d), and the yield was moderate (30 %).…”

Synthesis of Hydrophilic Phosphorus Ligands and Their Application in Aqueous‐Phase Metal‐Catalyzed Reactions

“…As already mentioned in the introduction to this chapter, the harsh reaction conditions usually associated with direct sulfonation are not compatible with all structural features of common phosphine ligands. Examples for oleum‐sensitive groups on alkyldiphenylphosphines are long alkyl chains (>C 6 ) or alkenyl substituents [35] . While alkyl chains longer than hexyl are cleaved, [36] the double bond of an alkenyl moiety would be protonated and thus susceptible to side reactions [35] …”