可取代的

According to the results of the examination, the stronger the electron-withdrawing protective group of imines, the better the cis-selectivity of the reaction, 68% yield, trans:cis is 99:1 diastereoselectivity could be leaded by Ts-imines (4-methyl-N-methylene-benzenesulfonaides) with a substituent [2,4-(CH3O)2C6H3], Substrate scope investigation revealed that a wide variety of ketenes and imines could react smoothly to afford corresponding,β-lactams.

实验结果表明，亚胺的保护基团吸电子能力越强，越有利于顺式产物的生成。对甲苯磺酰基保护的取代基为2，4-二甲氧苯基的亚胺参与的该反应可得到68%的产率，反式：顺式=99：1的非对映选择性。底物拓展过程中发现Staudinger反应适用于多种不同的亚胺与烯酮。

Firstly, phenyliodine diacetate was immobilized to the 2% cross-linked polystyrene or the liner polystyrene resin. The more iodine the resin had, the lower conversion to phenyliodine diacetate. We made our endeavor to extend the range of useful application of polystyrene supported phenyliodine diacetate in organic synthesis:(1) the reagent was used as an effective reagent of carbonyl regeneration from oximes and semicarbazones of ketones.(2) the reagent was also applied to the synthesis of 1, 3, 4-oxadiazoles, 1, 3-disubstituted-2-pyrazoline, 2-arylbenzoxazole from aldehyde N-acylhydrazones, aldehyde hydoazones and phenolic Schiff's bases respectively.

首先，我们以2％交联的聚苯乙烯和线性的聚苯乙烯树脂为载体，制备了聚合物负载的二醋酸碘苯，通过研究发现：(1)聚苯乙烯二醋酸碘苯是酮肟、缩氨脲有效的去保护试剂，不仅芳香酮，脂肪酮和α，β不饱和酮的肟、缩氨脲也能顺利转化为相应的酮，实现酮基的再生；(2)我们还利用此试剂，分别与醛的N-酰基苯、N-酰基苯腙及邻羟基芳亚胺反应，在温和的条件下发生成环反应，以良好的产率生成1，3，4-噁二唑、吡唑啉和二取代苯并噁唑等杂环化合物；(3)聚苯乙烯二醋酸碘苯还可有效地将邻羟基芳酮的酰腙经氧化、重排成1，2-二酰基苯。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。