Highly diastereoselective coordination of unsymmetrical cationic 2,2′-bipyridine ligands bearing a chiral amidinium substituent to [Re(CO)3Cl] and [Ir(PhPy)2]+ cores is reported. Binding strength and stereoselectivity have been correlated with the position of the amidinium group on the bipy. The 4-, 5- and 6-substituted ligands all produce C-[Re(CO)3(LH)Cl]X selectively, while only the 4-derivative gives
据报道,不对称阳离子
2,2'-联吡啶配体具有 [Re (CO) 3 Cl] 和 [Ir (PhPy) 2 ] +核心的手性脒取代物的高度非对映选择性配位。结合强度和立体选择性与双基上脒基的位置相关。4-、5- 和 6- 取代的
配体都选择性地产生C - [Re (CO) 3 (LH) Cl] X,而只有 4- 衍
生物优先形成 Δ- [Ir (Phpy) 2 (4- LH)] (BF 4 ) 2。