Departamento de Química Orgánica, Universidad de Valencia, 46100-Burjassot, Valencia, Spain.
J Org Chem. 2012 Nov 2;77(21):9693-701. doi: 10.1021/jo301778n. Epub 2012 Oct 16.
The palladium-catalyzed reaction of α-bromomethyl sulfoxides, carbon monoxide, and N-nucleophiles follows different reaction pathways according to the catalytic system and the reaction conditions. The Pd-xantphos catalyst affords high yields of α-sulfinyl amides by an aminocarbonylation process and is the first example of this type of transformation for a nonbenzylic sp(3)-hybridized carbon. On the other hand, the oxidative carbonylation of amines occurs with α-bromomethyl sulfoxides, carbon monoxide, and catalytic Pd(PPh(3))(4) under aerobic conditions, yielding ureas and oxalamides from either primary or secondary amines. The reaction with ambident nucleophiles such as amino alcohols was highly selective and took place exclusively at the amino group despite the presence of the alcohol functionality. In parallel to the reaction paths for simple amines, amino alcohols were converted into hydroxy sulfinyl amides when the reaction was catalyzed by Pd-xantphos, while Pd(PPh(3))(4) catalyst afforded cyclic carbamates. The alkoxycarbonylation reaction of bromomethyl sulfoxides with simple alcohols and CO leading to the corresponding sulfinyl esters is also described.
钯催化的α-溴甲基亚砜、一氧化碳和 N-亲核试剂的反应根据催化体系和反应条件遵循不同的反应途径。Pd-xantphos 催化剂通过氨基羰基化反应得到高收率的α-亚磺酰基酰胺,这是首例非苄基 sp(3)-杂化碳的此类转化。另一方面,在有氧条件下,α-溴甲基亚砜、一氧化碳和催化 Pd(PPh(3))(4)与胺发生氧化羰基化反应,从伯胺或仲胺生成脲和草酰胺。与氨基醇等两性亲核试剂的反应具有高度选择性,尽管存在醇官能团,但反应仅发生在氨基上。与简单胺的反应途径平行,当反应由 Pd-xantphos 催化时,氨基醇被转化为羟基亚磺酰基酰胺,而 Pd(PPh(3))(4)催化剂则得到环状碳酸酯。还描述了简单醇和 CO 与溴甲基亚砜的烷氧基羰基化反应,得到相应的亚磺酰基酯。