Molecular and crystal structures of N-alkoxy-N-chloroureas and N,N-dialkoxyureas were studied together with those of N-alkoxyureas as reference compounds. N-Alkoxy-N-chloroureas were found to have an elongated N—Cl bond and a shortened N–O(Alk) bond due to the nO(Alk)→σ*N–Cl anomeric effect. Alcoholysis of N-alkoxy-N-chloro derivatives of urea, N′-arylureas, and carbamates in the presence of silver trifluoroacetate leads to sterically hindered N,N-dialkoxyureas, N,N-dialkoxy-N′-arylureas, and N,N-dialkoxycarbamates, respectively.
研究了N-烷氧基-N-
氯脲和N,N-二烷氧基
脲的分子和晶体结构,同时以N-烷氧基
脲作为参考化合物。发现N-烷氧基-N-
氯脲具有拉长的N—Cl键和缩短的N–O(Alk)键,这归因于nO(Alk)→σ*N–Cl的异构效应。在
三氟乙酸银存在下,对N-烷氧基-N-
氯衍
生物、N′-芳基
脲和
氨基甲酸酯的醇解反应分别得到空间位阻较大的N,N-二烷氧基
脲、N,N-二烷氧基-N′-芳基
脲和N,N-二烷氧基
氨基甲酸酯。