2H NMR spectroscopy as a probe of the stereochemistry of enzymic reactions at prochiral centres
作者:James C. Richards、Ian D. Spenser
DOI:10.1016/s0040-4020(01)88666-x
日期:1983.1
In the conversion of cadaverine into Δ1-piperideine, of putrescine into Δ1-pyrroline, and of agmatine into 4-guanidinobutanal, catalyzed by hog kidney diamine oxidase (DAO) (E.C. 1.4.3.6 diamine: oxygen oxidoreductase (deaminating)), the si-H from C-1 of the substrate is removed while the re-H from C-1 of the substrate is maintained at the sp2 C atom of each of the products.
HOBT immobilized on macroporous polystyrene beads: a useful reagent for the synthesis of amides
作者:Kleanthis Dendrinos、Jeannie Jeong、Aristotle G. Kalivretenos
DOI:10.1039/a708273h
日期:——
Polymer-supported 1-hydroxybenzotriazole (P-HOBT), prepared from macroporous polystyrene beads, was used to synthesize amides from primary and secondary amines.
Selective Monoacylation of Symmetrical Diamines via Prior Complexation with Boron
作者:Zhongxing Zhang、Zhiwei Yin、Nicholas A. Meanwell、John F. Kadow、Tao Wang
DOI:10.1021/ol0300773
日期:2003.9.1
[reaction: see text] Pretreatment of a symmetrical primary or secondary diamine with 9-BBN prior to the addition of an acyl chloride significantly suppressed undesired diacylation, and the product of monoacylation predominated. The reactive preference is interpreted as the result of a selective deactivation of one nitrogen atom of the diamine by 9-BBN.
Taming diamines and acyl chlorides by carbon dioxide in selective mono-acylation reactions
作者:Jerik Mathew Valera Lauridsen、Margarita Poderyte、Ji-Woong Lee
DOI:10.1039/d2gc04478a
日期:——
acylation of diamines with corresponding acyl donors, using a protecting group, or with excess amounts of diamines to prevent unwanted diacylation reactions. Here we report a practical and atom-economical method to access monoamide and unsymmetric diamides with diamines and stoichiometric amounts of acylchlorides – the most accessible and highly reactive acyl donor. The reactivity of diamines can be
二酰胺普遍存在于有机分子的化学结构中,具有多种应用。这些二酰胺中的大多数是通过二胺与相应的酰基供体、使用保护基团或与过量的二胺进行酰化以防止不需要的二酰化反应而获得的。在这里,我们报告了一种实用且原子经济的方法,以使用二胺和化学计量的酰氯(最容易获得且反应性高的酰基供体)获得单酰胺和不对称二酰胺。二胺的反应性可以通过CO 2来控制作为单酰化反应的绿色、临时、无痕保护基团,实现高原子效率和低环境因素。我们证明了该方法具有广泛的底物范围和大规模反应的实用性,并进行了对照实验以阐明使用 CO 2获得的高选择性的来源。我们发现稀薄空气中的环境 CO 2会影响二胺单酰化的选择性,这意味着大气 CO 2在有机合成中具有普遍影响。
Rubber composition
申请人:SUMITOMO CHEMICAL COMPANY, LIMITED
公开号:EP0470776A1
公开(公告)日:1992-02-12
A rubber composition comprising a rubber, a filler and a diamide compound represented by the formula:
wherein X is hydrogen, alkyl of 1 to 18 carbon atoms, alkoxy of 1 to 18 carbon atoms, alkanoyl of 2 to 19 total carbon atoms, amino, nitro, cyano, hydroxy, carboxy or halogen, and n is an integer of 2 to 12. This rubber composition is increased in its loss factor and is useful for tires and rubber vibration isolators. For example, the resulting tires prepared from the rubber composition are improved in their gripping performance.