Use of Group 4 Bis(sulfonamido) Complexes in the Intramolecular Hydroamination of Alkynes and Allenes
作者:Lutz Ackermann、Robert G. Bergman、Rebecca N. Loy
DOI:10.1021/ja0361547
日期:2003.10.1
the intramolecularhydroamination of alkynes and allenes more efficiently than Cp-based species. We report here that electron-withdrawing and sterically demanding bis(sulfonamido) ligands lead to enhanced catalytic activity. Zirconium analogues have also been prepared, and the tosyl-substituted complex 20 has been structurally characterized. As in the titanium series, bis(sulfonamido) zirconium catalysts
Practical Enantioselective Synthesis of β-Lactones Catalyzed by Aluminum Bissulfonamide Complexes
作者:Thomas Kull、René Peters
DOI:10.1002/adsc.200700084
日期:2007.7.2
practical aluminum-bissulfonamide complex catalyzed enantioselective formation of β-lactones by [2+2] cycloaddition of ketene (generated in situ from acetyl bromide by dehydrobromination) with various α-unbranched and -branched aliphatic aldehydes is presented. The methodology offers the advantage of operational simplicity not only as the ligand synthesis requires just a single sulfonylation step from commercially
MgBr<sub>2</sub>-promoted enantioselective aryl addition of ArTi(O<sup>i</sup>Pr)<sub>3</sub> to ketones catalyzed by a titanium(<scp>iv</scp>) catalyst of N,N′-sulfonylated (1R,2R)-cyclohexane-1,2-diamine
作者:Chao-Chi Shu、Shuangliu Zhou、Han-Mou Gau
DOI:10.1039/c5ra18871g
日期:——
MgBr2-promoted asymmetric addition of ArTi(OiPr)3 to ketonescatalyzed by a titanium catalyst of N,N′-sulfonylated (1R,2R)-cyclohexane-1,2-diamines is reported, and results showed that the chiral N,N′-sulfonylated cyclohexane-1,2-diamines with electron-withdrawing groups could effectively catalyze asymmetric addition of ArTi(OiPr)3 to ketones to afford desired tertiary alcohols in good yields with
据报道,MgBr 2促进了N,N'-磺酰化(1 R,2 R)-环己烷-1,2-二胺的钛催化剂催化的酮类化合物向酮中不对称地添加ArTi(O i Pr)3,结果表明:具有吸电子基团的手性N,N'-磺酰化环己烷-1,2-二胺可以有效催化不对称地将ArTi(O i Pr)3加到酮上,以高收率提供所需的叔醇,并具有良好的对映选择性。到95%ee。
Synthesis, Structure, and Catalytic Properties of Bis[bis(sulfonamido)] Titanium Complexes
作者:Eva Royo、Juan M. Betancort、Timothy J. Davis、Patrick Carroll、Patrick J. Walsh
DOI:10.1021/om000443b
日期:2000.11.1
this work have also been used in the asymmetric addition of diethylzinc to aldehydes. This reaction is very efficient and gives excellent enantioselectivity with a wide variety of aldehydes. To determine if the TiL2 complexes were involved in the catalysis, an equilibrium mixture of the diastereomers C2-6homo/Cs-6homo was used in the asymmetric addition and compared with the catalyst generated under
Synthesis and Structural Study of Titanium Bis(sulfonamido) Bis(amide) Complexes
作者:Suzy Pritchett、Peter Gantzel、Patrick J. Walsh
DOI:10.1021/om9807755
日期:1999.3.1
of the titanium tetraamide Ti(NMe2)4 with various bis(sulfonamide) ligands resulted in the clean formation of the bis(sulfonamido)Ti(NMe2)2 complexes and N,N-dimethylamine. We have characterized the resulting racemic and resolved bis(sulfonamido)Ti(NMe2)2 complexes by X-ray crystallography to explore differences in the bonding and geometry of the ligand in these complexes. From the crystal structures