Sulfonium salts [R2S-CH2-OTf]+ OTf- 1a,b are synthetically versatile 1,1-biselectrophiles featuring the sulfonio- and triflato-substituents as leaving groups of differential nucleofugic power. Reactions with a number of neutral nucleophiles |Nu yield a series of novel sulfoniom ethylated onium salts [R2S-CH2-Nu]2+ 2OTf- 2 - 8 under very mild conditions. Structures of salts 2a, 5a and 6b were confirm ed by X -ray analysis. With certain N -hetarenes exchange of both nucleofuges in la was achieved, yielding the symmetrical 1,1-bisonium salts 9 and 10. With pyridine(derivatives) selective substitution of the sulfoniofunction in 1,1-bisonium systems 2a and 5a was also realized. These reactions represent typical examples of nucleophilic substitutions at geminally bisonio substituted Csp3 centers, which we recently have introduced as a novel variant of Sɴ2 reactivity.
砜盐[R2S-CH2-OTf]+ OTf- 1a,b是一种合成多功能的1,1-双亲电子受体,具有硫烷基和三氟甲烷基取代基作为不同核离散能力的离去基团。与一系列中性亲核试剂|Nu反应,在非常温和的条件下生成一系列新型硫烷基化的烷基化磺酸盐[R2S-CH2-Nu]2+ 2OTf- 2 - 8。盐2a、5a和6b的结构经X射线分析确认。通过对la中某些N-杂环化合物的反应,实现了两个核离散基团的交换,形成对称的1,1-双磺酸盐9和10。对于吡啶(衍生物),也实现了对1,1-双磺酸盐系统2a和5a中硫烷基功能的选择性取代。这些反应代表了我们最近引入的作为Sɴ2反应的一种新变体的烷基化双磺酸Csp3中的亲核取代的典型示例。