Catalytic asymmetric allylation of aldehydes using the chiral (salen)chromium(III) complexes
作者:Piotr Kwiatkowski、Wojciech Chaładaj、Janusz Jurczak
DOI:10.1016/j.tet.2006.03.032
日期:2006.5
aldehydes, catalyzed by chiral (salen)Cr(III) complexes, has been studied. The reaction proceeded smoothly for the reactive 2-oxoaldehydes and allyltributyltin in the presence of small amounts (1–2 mol %) of (salen)Cr(III)BF4 (1b) under mild, undemanding conditions. However, in the case of other simple aldehydes, the use of high-pressure conditions is required to obtain good yields. Classic chromium catalyst
已经研究了手性(salen)Cr(III)配合物催化烯丙基锡烷醛向乙醛酸酯和乙二醛以及简单的芳香族和脂肪族醛的对映选择性加成。在少量(1-2)摩尔(salen)Cr(III)BF 4(1b)的存在下,在温和,不苛刻的条件下,反应性2-氧醛和烯丙基三丁基锡的反应顺利进行。但是,在其他简单醛的情况下,需要使用高压条件才能获得良好的收率。经典的铬催化剂1b,可轻松从市售的氯化物络合物1a制备,通常以高收率得到对映体醇,对映体纯度为50-79%ee。在提出的模型的基础上,对立体化学结果进行了合理化。