Ferrocenyloxazoline-Derived Planar Chiral Palladacycles: C–H Activation, Transmetalation, and Reversal of Diastereoselectivity
作者:Ross A. Arthurs、David L. Hughes、Christopher J. Richards
DOI:10.1021/acs.organomet.9b00551
日期:2019.11.11
resulting S,Sp palladacycle. A similar 4:1 dr was obtained using Na2PdCl4 in MeOH. As an alternative approach, highly diastereoselective lithiation (dr >100:1) and transmetalation were investigated. Addition of PdX2(COD) (X = Cl, Br) to (S,Rp)-2-lithio-1-(2′-(4′-methylethyl)oxazolinyl)ferrocene resulted in double halide substitution and formation of cis-(S,S,Sp,Sp)-bis[2-(2′-(4′-methylethyl)oxazolinyl)ferrocene-1-C
发现(S)-2-二茂铁基-4-(甲基乙基)恶唑啉与Pd(OAc)2在CH 2 Cl 2中的重合进行了3.6:1的dr进行研究,有利于生成的S,S p palladacycle。使用Na 2 PdCl 4在MeOH中的溶液获得相似的4:1 dr 。作为一种替代方法,研究了高度非对映选择性锂化(dr> 100:1)和金属转移。在(S,R p)-2-lithio-1-(2'-(4'-甲基乙基)恶唑啉基)二茂铁中添加PdX 2(COD)(X = Cl,Br)导致双卤化物取代并形成顺式-(S,S,S p,S p)-双[2-(2'-(4'-甲基乙基)恶唑啉基)二茂铁-1- C,3' - N ]钯(II)(X = 42% Cl,X = Br的50%)。用HCl选择性地单原钯制得含有可移动的二茂铁基恶唑啉配体的S,S p palladacycle。将PdCl 2(MeCN)2加到乙腈中的硫醇环中,本身是由