In here we present the deoxygenation of the chalcogen oxides EO₂ (E = S, Se) with R-P(PMe₃), so-called phospha-Wittig reagents. The reaction of DABSO (DABCO·2SO₂) with R-P(PMe₃) (R = Mes*, 2,4,6-tBu₃-C₆H₂; ^MesTer, 2,6-(2,4,6-Me₃-C₆H₂)₂-C₆H₃) resulted in the formation of thiadiphosphiranes (RP)₂S (1:R), while selenadiphosphiranes (RP)₂Se (2:R) were afforded with SeO₂, both accompanied by the formation of OPMe₃. Utilizing the sterically more encumbered ^DipTer-P(PMe₃) (^DipTer = 2,6-(2,6-iPr₂-C₆H₃)₂-C₆H₃) a different selectivity was observed and (^DipTerP)₂Se (2:^DipTer) along with [Se(μ-P^DipTer)]₂ (3:^DipTer) were isolated as the Se-containing species in the reaction with SeO₂. Interestingly, the reaction with DABSO (or with equimolar ratios of SeO₂ at elevated temperatures) gave rise to the formation of the OPMe₃-stabilized dioxophosphorane (phosphinidene dioxide) ^DipTerP(O)₂-OPMe₃ (4:^DipTer) as the main product. This contrasting reactivity can be rationalized by two potential pathways in the reaction with EO₂: (i) a Wittig-type pathway and (ii) a pathway involving oxygenation of the phospha-Wittig reagents and release of SO. Thus, phospha-Wittig reagents are shown to be useful synthetic tools for the metal-free deoxygenation of EO₂ (E = S, Se).

中文翻译：

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硫族氧化物 EO2 (E = S, Se) 与磷-Wittig 试剂脱氧

在这里，我们介绍了硫族氧化物 EO ₂ (E = S, Se) 与 RP(PMe ₃ ) 的脱氧反应，即所谓的磷-Wittig 试剂。DABSO (DABCO·2SO ₂ ) 与RP(PMe ₃ ) 的反应 (R = Mes*, 2,4,6- t Bu ₃ -C ₆ H ₂ ; ^Mes Ter, 2,6-(2,4,6 -Me ₃ -C ₆ H ₂ ) ₂ -C ₆ H ₃ ) 导致形成硫代二膦 (RP) ₂ S ( 1:R )，而硒二膦 (RP) ₂ Se ( 2:R) 与 SeO ₂一起提供，两者都伴随着 OPMe ₃的形成。利用空间位阻更大的^Dip Ter-P(PMe ₃ ) ( ^Dip Ter = 2,6-(2,6-iPr ₂ -C ₆ H ₃ ) ₂ -C ₆ H ₃ ) 观察到不同的选择性并且 ( ^Dip TerP ) ₂ Se ( 2: ^Dip Ter ) 和 [Se(μ-P ^Dip Ter)] ₂ ( 3: ^Dip Ter ) 在与 SeO _{2的反应中被分离为含硒物质}. 有趣的是，与 DABSO 的反应（或在高温下与等摩尔比的 SeO ₂反应）导致形成 OPMe ₃ -稳定的二氧代正膦（二氧化亚膦）^Dip TerP(O) ₂ -OPMe ₃ ( 4: ^Dip Ter ) 作为主要产品。这种对比反应性可以通过与 EO ₂反应的两个潜在途径合理化：(i) Wittig 型途径和 (ii) 涉及磷酸-Wittig 试剂氧化和 SO 释放的途径。_{因此，phospha-Wittig 试剂被证明是用于 EO 2} (E = S, Se)无金属脱氧的有用合成工具。