UNIFAC-DMD法预测烷烃-氨的汽液相平衡

烷烃-氨的汽液相平衡模型是计算爱因斯坦制冷循环的重要数据。然而在设计氨-水-异戊烷的爱因斯坦制冷循环的过程中,从文献中查阅不到异戊烷-氨的相平衡数据。采用商业软件中基团贡献法UNIFAC-DMD自带的数据库所预测的结果也不尽人意,不能得到特征的蝶形相图。本文利用基团贡献法的原理,通过使用模拟软件,应用文献中得到的丙烷-氨和正丁烷-氨体系的相平衡数据,拟合基团贡献法UNIFAC-DMD中的CH_2、NH_3的含对温度修正的基团交互参数a_(CH_2NH_3,1)/K,a_(CH_2NH_3,2),a_(CH_2NH_3,3)/K^(-1)和a_(NH_3CH_3,1)/K,a_(NH_3CH_3,2),a_(NH_3CH_3,3)/K^(-1)。拟合得到上述基团交互参数值分别为-1 995.4,18.51,-0.037,11 565.3,-68.98,和0.111 4。将此组新参数替换原有基团贡献法的数据库参数,重新预测烷烃-氨的相平衡,成功预测得到了蝶形相图。

Copper(I)/Sa BOX catalyzed highly diastereo- and enantio-selective cyclopropanation of cis-1,2-disubstituted olefins with a-nitrodiazoacetates

A copper-catalyzed highly stereoselective cyclopropanation of 1,2-disubstituted olefins with α-nitrodiazo acetates has been developed, giving the desired products in up to 97 % yields, up to 〉99/1 dr and up to 98 % ee, which provides an efficient access to the synthesis of optical active cyclopropane α-amino acids and unnatural α-amino acid derivatives.