Binolate complexes of lithium, zinc, aluminium, and titanium; preparations, structures, and studies of lactide polymerization

被引:131
作者
Chisholm, MH
Lin, CC
Gallucci, JC
Ko, BT
机构
[1] Ohio State Univ, Dept Chem, Newman & Wolfrom Labs, Columbus, OH 43210 USA
[2] Natl Chung Hsing Univ, Dept Chem, Taichung 402, Taiwan
关键词
D O I
10.1039/b211582b
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
The reaction of racemic 5,5',6,6'-tetramethyl-3,3'-di-tert-butyl-1,1'-biphenyl-2,2'-diol (biphenolate-H-2) with 4 mol equiv. of (BuLi)-Bu-n yields [(mu(3),mu(3)-biphenolate)(2)Li-4((BuLi)-Bu-n)(4)] (1) in high yield. I further reacts with 4 mol equiv. of 2,4dimethyl-3-pentanol in the presence of tetrahydrofuran (THF) or cyclohexene oxide (CyHO) to give the lithium aggregate [(mu,mu-biphenotate)Li-2(mu(3)-OCH(Pr-i)(2))(2)Li-2(L)(2)] (2-THF, L = THF; 2-CyHO, L = CyHO). Treatment of biphenolate-H2 with 3 mol equiv. of ZnEt2, followed by addition of 2 mol equiv. of 2,4-dimethyl-3-pentanol provides the zinc complex [(mu,mu-biphenolate)Zn(mu-OCH(Pr-i)(2))(2)Zn2Et2] (3). Aluminium alkoxide incorporating biphenolate ligand can also be obtained via a similar synthetic route. The compound [(mu-biphenolate)AlMe(mu-OCH(Pr-i)(2))AlMe2] (4) is prepared from the reaction of biphenolate-H2 with 2 mol equiv. of AlMe, in the presence of I mol equiv. of 2,4dimethyl-3-pentanol. The titanium (4+) binolate complex [(biphenolate)Ti2Cl6] (5) is synthesized from the reaction of biphenolate-H-2 and 2 mol equiv. of TiCl4. In addition, 2-THF, 3, and 4 have been examined for rac-lactide polymerization, and the comparative studies of polymerization are also presented.
引用
收藏
页码:406 / 412
页数:7
相关论文
共 38 条
[1]   Catalytic enantioselective ring-closing metathesis by a chiral biphen-Mo complex [J].
Alexander, JB ;
La, DS ;
Cefalo, DR ;
Hoveyda, AH ;
Schrock, RR .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1998, 120 (16) :4041-4042
[2]   Molecular design of single site catalyst precursors for the ring-opening polymerization of cyclic ethers and esters. 2. Can ring-opening polymerization of propylene oxide occur by a cis-migratory mechanism? [J].
Antelmann, B ;
Chisholm, MH ;
Iyer, SS ;
Huffman, JC ;
Navarro-Llobet, D ;
Pagel, M ;
Simonsick, WJ ;
Zhong, WQ .
MACROMOLECULES, 2001, 34 (10) :3159-3175
[3]   STRUCTURALLY WELL CHARACTERIZED BINAPHTHOLATE TITANIUM CHLORIDE LEWIS-ACIDS - EVIDENCE FOR ACTIVE DINUCLEAR CATALYSTS IN A DIELS-ALDER PROCESS [J].
BOYLE, TJ ;
EILERTS, NW ;
HEPPERT, JA ;
TAKUSAGAWA, F .
ORGANOMETALLICS, 1994, 13 (06) :2218-2229
[4]   Trapping of n-butyllithium dimer by a trilithiated derivative of {Al[N(H)But]3}2 [J].
Brask, JK ;
Chivers, T ;
Yap, GPA .
CHEMICAL COMMUNICATIONS, 1998, (22) :2543-2544
[5]   Polymerization of lactide with zinc and magnesium β-diiminate complexes:: Stereocontrol and mechanism [J].
Chamberlain, BM ;
Cheng, M ;
Moore, DR ;
Ovitt, TM ;
Lobkovsky, EB ;
Coates, GW .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2001, 123 (14) :3229-3238
[6]   Reactions of 2,2′-methylenebis(4-chloro-6-isopropyl-3-methylphenol) with trimethylaluminum:: Highly efficient catalysts for the ring-opening polymerization of lactones [J].
Chen, HL ;
Ko, BT ;
Huang, BH ;
Lin, CC .
ORGANOMETALLICS, 2001, 20 (24) :5076-5083
[7]   Single-site catalysts for ring-opening polymerization:: Synthesis of heterotactic poly(lactic acid) from rac-lactide [J].
Cheng, M ;
Attygalle, AB ;
Lobkovsky, EB ;
Coates, GW .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1999, 121 (49) :11583-11584
[8]   Single-site β-diiminate zinc catalysts for the alternating copolymerization of CO2 and epoxides:: Catalyst synthesis and unprecedented polymerization activity [J].
Cheng, M ;
Moore, DR ;
Reczek, JJ ;
Chamberlain, BM ;
Lobkovsky, EB ;
Coates, GW .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2001, 123 (36) :8738-8749
[9]   Three-coordinate zinc amide and phenoxide complexes supported by a bulky Schiff base ligand [J].
Chisholm, MH ;
Gallucci, JC ;
Zhen, HH ;
Huffman, JC .
INORGANIC CHEMISTRY, 2001, 40 (19) :5051-+
[10]   A comparative study in the ring-opening polymerization of lactides and propylene oxide [J].
Chisholm, MH ;
Navarro-Llobet, D ;
Simonsick, WJ .
MACROMOLECULES, 2001, 34 (26) :8851-8857