Tripathi Santosh K, Patel Upali, Roy Dipankar, Sunoj Raghavan B, Singh Harkesh B, Wolmershäuser Gotthelf, Butcher Ray J
Department of Chemistry, Indian Institute of Technology, Bombay, Powai, 400076 Mumbai, India.
J Org Chem. 2005 Nov 11;70(23):9237-47. doi: 10.1021/jo051309+.
[Structure: see text]. The synthesis and characterization of a series of organochalcogen (Se, Te) compounds derived from benzyl alcohol 13 are described. The synthesis of the key precursor dichalcogenides 15, 22, and 29 was achieved by the ortho-lithiation route. Selenide 18 was obtained by the reaction of the dilithiated derivative 14 with Se(dtc)2. Oxidation of 15 and 22 with H2O2 afforded the corresponding cyclic ester derivatives 17 and 24, respectively. Oxidation of selenide 18 with H2O2 affords the spirocyclic compound 19. The presence of intramolecular interactions in dichalcogenides 15 and 22 has been proven by single-crystal X-ray studies. The cyclic compounds 17 and 19 have also been characterized by single-crystal X-ray studies. GP(X)-like antioxidant activity of selenium compounds has been evaluated by the coupled bioassay method. Density functional theory calculations at the mPW1PW91 level on ditelluride 22 have identified a fairly strong nonbonding interaction between the hydroxy oxygen and tellurium atom. The second-order perturbation energy obtained through NBO analysis conveys the involvement of n(O) --> sigma(Te-Te) orbital overlap in nonbonding interaction. Post wave function analysis with the Atoms in Molecules (AIM) method identified distinct bond critical point in 15 and 22 and also indicated that the nonbonding interaction is predominantly covalent. Comparison between diselenide 15 and ditelluride 22 using the extent of orbital interaction as well as the value of electron density at the bond critical points unequivocally established that a ditelluride could be a better acceptor in nonbonding interaction, when the hydroxy group acts as the donor.
[结构:见正文]。描述了一系列源自苯甲醇13的有机硫属元素(硒、碲)化合物的合成与表征。关键前体二硫属化物15、22和29通过邻位锂化路线合成。硒化物18通过二锂化衍生物14与Se(dtc)₂反应得到。15和22用H₂O₂氧化分别得到相应的环状酯衍生物17和24。硒化物18用H₂O₂氧化得到螺环化合物19。单晶X射线研究证明了二硫属化物15和22中存在分子内相互作用。环状化合物17和19也通过单晶X射线研究进行了表征。通过偶联生物测定法评估了硒化合物的类GP(X)抗氧化活性。在mPW1PW91水平上对二碲化物22进行的密度泛函理论计算确定了羟基氧与碲原子之间相当强的非键相互作用。通过NBO分析获得的二阶微扰能表明n(O)→σ(Te-Te)轨道重叠参与了非键相互作用。用分子中的原子(AIM)方法进行的波函数后分析在15和22中确定了明显的键临界点,并且还表明非键相互作用主要是共价的。使用轨道相互作用程度以及键临界点处的电子密度值对二硒化物15和二碲化物22进行比较,明确地确定了当羟基作为供体时,二碲化物在非键相互作用中可能是更好的受体。