多牙氮配位基及其具金屬金屬鍵之雙金屬錯合物的合成與其催化應用

Abstract

在文獻中，多牙氮配位基2,7 –Di(2-pyridyl)-1,8-naphthyridine (bpnp)及其金屬錯合物已被廣泛研究，但未有人針對其金屬錯合物之催化反應進行探討。故在本論文中，我們使用2-(Tributylstannyl)pyridine及2,7-Dichloro-1,8-naphthyridine，在鈀金屬的催化之下，進行Stille coupling，即可成功合成出bpnp。並以bpnp為主體配位基，與零價的Pd2(dba)3及兩價的PdCl2(PhCN)2反應，即可合成出具有金屬金屬鍵之雙鈀金屬錯合物。另外，我們也使用RuCl3及bpnp，以乙醇作為反應溶劑，迴流24小時後，即可合成出雙釕金屬錯合物(Ru2Cl6(bpnp))，最後則是利用Ru2Cl6(bpnp)當作催化劑，進行一系列催化反應。 雙釕金屬錯合物可應用在氫轉移反應上，而氫轉移反應主要是使用異丙醇作為hydrogen acceptor，在鹼性的條件底下，將一系列苯乙酮衍生物還原成醇類，無論針對具有拉或推電子基的苯乙酮衍生物而言，都具有不錯的催化活性。另外雙釕金屬錯合物也可使用在N-alkylation反應，此反應主要是使用醇類，在釕金屬的催化之下，氧化成醛或酮類，再與一級胺反應形成亞胺化合物，最後再經釕錯合物還原成二級胺。論文中所合成之雙釕金屬錯合物，針對具推電子之苯甲醇及長碳鍵之一級醇都有良好的催化活性。

2,7 –Di(2-pyridyl)-1,8-naphthyridine (bpnp) is a multiple pyridinyl nitrogen donor, which is able to bind with metal ions in a chelating manner. Its metal complexes particularly the ruthenium and copper, have known for a while, but catalytic activity of the related species has not been disclosed. In this work, the Stille coupling reaction of 2-(tributylstannyl)pyridine with 2,7-dichloro-1,8-naphthyridine provided the desired bpnp ligand efficiently. Preparations of dipalladium [Pd2Cl(H2O)(bpnp)]Cl and diruthenium Ru2Cl6(bpnp) complexes were achieved. With the use of diruthenium complex as the pre-catalyst, reduction of acetophenone derivatives into their corresponding alcohols under hydrogen-transfer conditions was studied. Ru2Cl6(bpnp) can also be used as the catalyst to promote the N-alkylation reaction of amine with an alcohol. In this reaction, the alcohol was oxidized to form the corresponding aldehyde, which is subsequently reacted with an amine to form the corresponding imine. Further reduction of C=N bond by the ruthenium hydride species produced the secondary amine product.