Lan Ruichen, Yager Brock, Jee Yoonsun, Day Cynthia S, Jones Amanda C
Chemistry, Wake Forest University, 1834 Gulley Rd., Winston-Salem, NC, 27109, USA.
Beilstein J Org Chem. 2024 Feb 29;20:479-496. doi: 10.3762/bjoc.20.43. eCollection 2024.
Kinetic studies on the intramolecular hydroamination of protected variants of 2,2-diphenylpent-4-en-1-amine were carried out under a variety of conditions with cationic gold catalysts supported by phosphine ligands. The impact of ligand on gold, protecting group on nitrogen, and solvent and additive on reaction rates was determined. The most effective reactions utilized more Lewis basic ureas, and more electron-withdrawing phosphines. A DCM/alcohol cooperative effect was quantified, and a continuum of isotope effects was measured with low KIE's in the absence of deuterated alcoholic solvent, increasing to large solvent KIE's when comparing reactions in pure MeOH to those in pure MeOH-. The effects are interpreted both within the context of a classic gold π-activation/protodeauration mechanism and a general acid-catalyzed mechanism without intermediate gold alkyls.
在多种条件下，使用由膦配体支撑的阳离子金催化剂，对2,2-二苯基戊-4-烯-1-胺的保护变体进行分子内氢胺化的动力学研究。确定了配体对金、氮上保护基团以及溶剂和添加剂对反应速率的影响。最有效的反应使用了更多路易斯碱性的脲和更多吸电子的膦。量化了二氯甲烷/醇的协同效应，并测量了一系列同位素效应，在没有氘代醇溶剂的情况下KIE值较低，当比较纯甲醇与纯甲醇-d中的反应时，溶剂KIE值增大。这些效应在经典的金π-活化/质子脱金机理以及没有中间体金烷基的一般酸催化机理的背景下进行了解释。
