Record-Breaking Steric Crowding in Trialkylamines Prepared by Oxidative Ring Opening
Record-Breaking Steric Crowding in Trialkylamines Prepared by Oxidative Ring Opening
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氧化开环制备三烷基胺的空间拥挤现象创纪录
DOI：
10.1055/s-0040-1707294
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
R. Weber
中科院分区：
文献类型：
--
作者：
K. Banert;M. Heck;A. Ihle;E. Michael;R. Weber
烯属杂环胺的环氧化和随后的酸催化水解或在四氧化锇的帮助下直接二羟基化产生二醇，其在四乙酸铅存在下发生环裂解，得到3-异丙基-2,2,4,4-四甲基-3-氮杂己二醛和3-叔丁基-2,2,4,4-四甲基-3-氮杂戊二醛。由于快速的分子内醇醛反应，前一种二醛是高度不稳定的模型化合物，而后一种产物被证明在室温下是可分离的。此外，该化合物是第一个开链三叔烷基胺，创造了叔胺空间拥挤的新记录。当 3-叔丁基-2,2,4,4-四甲基-3-氮杂戊二醛的醛单元转化为其他官能团时，观察到霍夫曼样消除反应或闭环反应的强烈倾向，因为两种类型的反应都会导致空间应力的显着降低。
Epoxidation of olefinic heterocyclic amines and subsequent acid-catalyzed hydrolysis or alternatively the direct dihydroxylation with the help of osmium tetroxide led to diols, which underwent ring cleavage in the presence of lead tetraacetate to give 3-isopropyl-2,2,4,4-tetramethyl-3-azahexanedial and 3-tert-butyl-2,2,4,4-tetramethyl-3-azapentanedial. Whereas the former dialdehyde is a highly unstable model compound because of a rapid intramolecular aldol reaction, the latter product proves to be isolable at room temperature. Furthermore, this compound is the first open-chain tri-tert-alkylamine establishing in a new record of steric crowding in tertiary amines. Strong tendencies to a Hofmann-like elimination reaction or to ring-closing reactions were observed when the aldehyde units of 3-tert-butyl-2,2,4,4-tetramethyl-3-azapentanedial were transformed into other functionalities, since both types of reactions led to a significantly decrease of the steric stress.
DOI：
10.1002/cber.19580910223
发表时间：
1958-01-01
期刊：
CHEMISCHE BERICHTE-RECUEIL
影响因子：
--
作者：
HUNIG, S;KIESSEL, M
通讯作者：
KIESSEL, M
DOI：
--
发表时间：
--
期刊：
影响因子：
--
作者：
H. Pauly
通讯作者：
H. Pauly