Hydrogen-bonding cyclodiphosphazanes: superior effects of 3,5-(CF3)2-substitution in anion-recognition and counter-ion catalysis
Hydrogen-bonding cyclodiphosphazanes: superior effects of 3,5-(CF3)2-substitution in anion-recognition and counter-ion catalysis
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DOI：
10.1039/c7nj04660j
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发表时间：
2018-03
影响因子：
3.3
通讯作者：
F. Wolf;J. Neudörfl;B. Goldfuss
中科院分区：
文献类型：
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作者：
F. Wolf;J. Neudörfl;B. Goldfuss
具有多种结构修饰的新HB-环二磷（V）氮烷，例如磷原子被硫和氧原子不对称取代以及苯基-（O（P）/S（P）-13）或3，5-（CF 3）2-C 6 H 3-取代（O（P）/S（P）-14）和3，合成了5-F_2C_6H_3取代的环二磷（V）氮烷，其磷原子上有氧（O（P）~（15））或硫（S（P）~（16））取代。这些新体系与苯基-（11）和3，5-（CF_3）_2-C_6H_3-取代的硫取代环二磷（V）氮烷（12）一起用于氯离子和乙酸根阴离子的还原。将这些HB-系统与先前建立的参考系统，即环二磷（V）氮烷（4，5）、硫脲（20）和方酰胺（21，22）进行比较。环二磷（V）氮烷部分中的硫族元素原子从氧（O（P）-5）到硫（O（P）/S（P）-14，S（P）-12）的修饰揭示阴离子结合能力的降低。3，5-（CF 3）2-C6 H3取代的O（P）-环二磷（V）氮烷5具有最强的阴离子结合作用（氯化物：log[K] 5.91，log[K]乙酸盐：6.06）在乙腈中，甚至超过了已建立的硫脲20（氯化物：log[K] 4.30，乙酸盐：log[K] 5.47）以及方酰胺21（氯化物：log[K] 4.92，乙酸盐：log[K] 4.24）和22（氯化物：log[K] 5.13，乙酸盐：log[K] 5.37）。计算研究证实3，5-（CF 3）2-C6 H3取代的5是本文研究的最强阴离子结合环二磷（V）氮烷，计算的结合能ΔGin-out·Cl为−21.1 kcal mol−1，ΔGin-out·OAc为−14.3 kcal mol−1，超过硫脲20（ΔGin-out·Cl = −19.10 kcal mol−1，ΔGin-out·OAc = −13.81 kcal mol−1）。在N-酰基-Mannich反应中检测了3，5-（CF 3）2-C6 H3取代的环二磷（V）氮烷5的催化效率，与替代的氢键催化剂二（1-萘基）硅烷二醇28相比，显示出显著更高的反应性（高达45%产率）。在所有这些应用中，3，5-（CF 3）2-C6 H3取代模式与环二磷（V）氮烷骨架中的O（P）-基团组合的优越性是明显的。
New HB-cyclodiphosph(V)azanes with a variety of structural modifications, e.g. unsymmetrical substitution of phosphorus atoms with sulfur and oxygen atoms as well as either phenyl- (O(P)/S(P)-13) or 3,5-(CF3)2-C6H3-substitution (O(P)/S(P)-14) and 3,5-F2C6H3-substituted cyclodiphosph(V)azanes with either oxygen (O(P)-15) or sulfur (S(P)-16) substitution at the phosphorus atoms, are synthesized. These new systems are employed together with sulfur substituted cyclodiphosph(V)azanes with phenyl- (11) and 3,5-(CF3)2-C6H3-substitution (12) in recognitions of chloride and acetate anions. These HB-systems are compared to the previously established reference systems, i.e. cyclodiphosph(V)azanes (4, 5), thiourea (20) and squaramides (21, 22). Modifications of the chalcogen atom in the cyclodiphosph(V)azane moieties from oxygen (O(P)-5) to sulfur (O(P)/S(P)-14, S(P)-12) reveal a decrease in anion binding capabilities. 3,5-(CF3)2-C6H3 substituted O(P)-cyclodiphosph(V)azane 5 exhibits the strongest anion binding effect (chloride: log[K] 5.91, log[K] acetate: 6.06) in acetonitrile, surpassing even the established thiourea 20 (chloride: log[K] 4.30, log[K] acetate: 5.47) as well as squaramides 21 (chloride: log[K] 4.92, acetate: log[K] 4.24) and 22 (chloride: log[K] 5.13, acetate: log[K] 5.37). Computational studies confirm 3,5-(CF3)2-C6H3 substituted 5 to be the strongest here studied anion-binding cyclodiphosph(V)azane with computed binding energies ΔGin–out·Cl of −21.1 kcal mol−1 and ΔGin–out·OAc of −14.3 kcal mol−1, surpassing thiourea 20 (ΔGin–out·Cl = −19.10 kcal mol−1, ΔGin–out·OAc = −13.81 kcal mol−1). The catalytic efficiency of 3,5-(CF3)2-C6H3 substituted cyclodiphosph(V)azane 5 is examined in a N-acyl-Mannich reaction, showing a significantly higher reactivity (up to 45% yield) compared to the alternative hydrogen-bonding catalyst di(1-naphthyl)silanediol 28. In all these applications, the superiority of the 3,5-(CF3)2-C6H3 substitution pattern in combination with O(P)-groups in the cyclodiphosph(V)azane scaffold is apparent.