Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science , Soochow University , Suzhou 215123 , People's Republic of China.
Inorg Chem. 2018 Jul 16;57(14):8568-8580. doi: 10.1021/acs.inorgchem.8b01292. Epub 2018 Jun 26.
Treating a scandium mixed alkyl/diaryloxide complex with phosphino-substituted alcohols resulted in the formation of scandium mixed alkoxyl/diaryloxide complexes Sc[OC(CH)CHPR][O-2,6- tBu-CH][THF] (6, R = Ph; 8, R = tBu). The reactivity of Sc-based Lewis pair complexes 6 and 8 toward a wide range of substrates was investigated. A ligand substitution reaction occurred when complex 6 was treated with benzophenone. The reaction of complex 6 with sulfur afforded a phosphane oxidative product. Complexes 6 and 8 also exhibited typical Sc/P frustrated Lewis pair (FLP) reactivity. They added to the carbonyl group of phenyl isocyanate to form seven-membered metallacycles. Complex 6 underwent selective Sc/P 1,4-addition reactions with α,β-unsaturated carbonyl compounds to give the corresponding nine-membered metallacyclic products. The reaction of 6 with 0.5 mol of dimethyl acetylenedicarboxylate led to the formation of bicyclo[7.7.0]cetane-derived metallacycle 16 in a distinctive double 1,4-addition pattern. With benzil complex 6 underwent a 1,4-addition reaction to afford a cis-enediolate which was coordinated to the Sc/P FLP through Sc-O and P-O bonds. Treatment of complex 6 with cyclopropyl phenyl ketone afforded the 10-membered metallaheterocycle 18, in which a scandium Lewis acid added to the oxygen atom and the phosphine Lewis base attacked the cyclopropyl group with ring opening. A ring-opening reaction also took place when epoxycyclohexane was employed as a substrate. Complex 6 successfully cleaved the C-Br bond of benzyl bromide to give zwitterionic complex 20 with newly formed Sc-Br and P-C bonds. Scandium phosphazine complex 21 was generated by a Sc/P 1,1-addition to the terminal nitrogen atom of (trimethylsilyl)diazomethane. Aided by the phosphorus Lewis base, scandium Lewis acid was able to abstract chloride from (PhP)AuCl to produce heterobimetallic Sc/Au complexes 22 and 23. Many complexes in this study were characterized by single-crystal X-ray diffraction.
用膦取代的醇处理钪混合烷基/二芳氧基配合物，得到钪混合烷氧基/二芳氧基配合物 Sc[OC(CH)CHPR][O-2,6- tBu-CH][THF]（6，R = Ph；8，R = tBu）。研究了基于 Sc 的路易斯对配合物 6 和 8 对各种底物的反应性。当配合物 6 与二苯甲酮反应时，发生了配体取代反应。配合物 6 与硫的反应生成了膦氧化产物。配合物 6 和 8 也表现出典型的 Sc/P 受阻路易斯对（FLP）反应性。它们加成到苯异氰酸酯的羰基上，形成七元金属环。配合物 6 与α，β-不饱和羰基化合物选择性地进行 Sc/P 1,4-加成反应，得到相应的九元金属环产物。配合物 6 与 0.5 摩尔二甲基丙二酸盐反应，以独特的双 1,4-加成模式形成双环[7.7.0]癸烷衍生的金属环 16。与二苯甲酮配合物 6 发生 1,4-加成反应，生成顺-烯二醇，其通过 Sc-O 和 P-O 键与 Sc/P FLP 配位。用环丙基苯基酮处理配合物 6，得到 10 元金属杂环 18，其中 Sc 路易斯酸加成到氧原子上，膦路易斯碱进攻环丙基，开环。当环氧化环己烷作为底物时，也发生了开环反应。配合物 6 成功地裂解了苄基溴的 C-Br 键，生成了具有新形成的 Sc-Br 和 P-C 键的两性离子配合物 20。通过与末端氮原子的 Sc/P 1,1-加成，生成了钪磷嗪配合物 21。在磷路易斯碱的辅助下，钪路易斯酸能够从（PhP）AuCl 中提取氯，生成杂双金属 Sc/Au 配合物 22 和 23。本研究中的许多配合物都通过单晶 X 射线衍射进行了表征。
