katalysens katalysen:二十七。Rh-komplexe mit von tropolon abgeleiteten optisch aktiven配体
摘要:
在对苯二酚中,氧原子逐步被NC★HMePh基团取代。将所得化合物作为阴离子配体引入Rh(COD)配合物中。新的配体和配合物进行了分析和光谱表征。通过NOE 1 H NMR差光谱法确定对苯二甲酸酯阴离子的Rh(COD)配合物中NCH(Me)(Ph)取代基的构象。使用来自[Rh(COD)Cl] 2的原位催化剂和新的配体以及新的配合物,在苯乙酮与二苯基硅烷的不对称氢化硅烷化中仅获得了很小的光诱导。当使用(+)-norphos和(-)-diop作为助催化剂,而使用新的络合物作为前催化剂时,对映体过量分别上升至5%和33%。
Cyclooctatetraene complexes of yttrium and the lanthanides with chiral and achiral aminotroponiminates
摘要:
The combination of dilithium- 1,4-bis(trimethylsilyl)cyclooctatetraene Li-2(1,4-(Me3Si)(2)C8H6). with anhydrous yttrium or lutetium trichloride and potassium N-isopropyl-2-(isopropylamino)troponiminate K{('Pr)(2)ATT}. leads to the corresponding mono cyclooctatetraene complexes [{eta (8)-1,4-(Me3Si)(2)C8H6} Ln{('Pr)(2)ATI}(THF)] (Ln = Y (1a), Lu (1b)). The solid-state structure of 1a was established by single-crystal X-ray diffraction. Using the same synthetic strategy, the chiral complex [{eta (8)-1,4-(Me3Si)(2)C8H6)Y {((S)-PhCHCH3)(2)ATI} (THF)] (2) can be obtained by using the enantiomerically pure ligand, potassium N-(S)-1-phenylethyl-2-((S)-1-phenylethylamino)troponiminate, K{(S)-PhCHCH3)(2)ATI. Furthermore, [(eta (8)-C8H8)Sm {('Pr)(2)ATI}-(THF)] (3) was obtained by the reaction of {(C8H8)SmI(THF)] and K{('Pr)(2)ATI). (C) 2001 Elsevier Science B.V. All rights reserved.