부산대학교 도서관

The synthesis and characterization of a series of newdiamido-thorium(IV)and diamido-uranium(IV) halide and alkyl complexes supported by threedifferent diamido-ether ligands are reported. Reaction of ThCl4·2DME with [(RNSiMe2)2O]Li2([RNON]Li2) in DME when R = tBu gives [tBuNON]ThCl5Li3·DME (1), when R = iPr2Ph in diethyl ether [iPr2PhNON]ThCl3Li·DME (3) is prepared. Reaction of UCl4with [iPr2PhNON]Li2in diethyl ether gives {[iPr2PhNON]UCl2}2(4). Reaction of ThCl4·2DMEwith Li2[(iPr2PhNCH2CH2)2O] ([iPr2PhNCOCN]Li2) in DME gives [iPr2PhNCOCN]ThCl2·DME (5). The addition of 2 equiv of LiCH2SiMe3to 1and 5resulted in salt- and base-free [tBuNON]Th(CH2SiMe3)2(7) and [iPr2PhNCOCN]Th(CH2SiMe3)2(9), respectively. Complexes 1, 3, 4, 7, and 9, as well aspreviously reported {[tBuNON]UCl2}2(2), [tBuNON]U(CH2SiMe3)2(6), and [iPr2PhNCOCN]U(CH2SiMe3)2(8) were examined as catalystsfor the intramolecular hydroamination of a series of aminoalkenes.Complexes 6–9were shown to facilitatethe formation of 2-methyl-4,4-diphenylpyrrolidine from 2,2-diphenyl-1-amino-4-penteneat room temperature. For 9, this reaction occurs in lessthan 15 min, while for other dialkyls 6–8, the reaction takes less than 2 h. Dihalides 1and 2facilitated the same reaction at 60 °C in4 h, while 3and 4showed no activity underthe same conditions. Dialkyl complexes 7–9were examined for further reactivity with different substrates.The uranium dialkyl 8was more active than 7and 9for the cyclization of 2,2-diphenyl-1-amino-5-hexeneand 2,2-diphenyl-1-amino-6-heptene, as well as more active in thecyclization of N-methyl-2,2-diphenyl-1-amino-4-pentene,a secondary amine. All three dialkyls became less active when thesteric bulk of the gem-substituents was decreasedfrom diphenyl to cyclopentyl; reactivity further decreased when thesteric bulk of the substituents was decreased further to hydrogen. [ABSTRACT FROM AUTHOR]