The present application relates to a process for preparing a dicarboxylic acid or dicarboxylic ester according to general formula (IV) R1OOC-(CH2)m-CH2CH2-(CH2)y-COOR4 (IV), comprising the steps of subjecting alkenoic acid or alkenoate of formula (II) R1OOC-(CH2)m-CH=CH-(CH2)x-H (II) to a metathesis reaction in the presence of a metathesis catalyst to form a longer-chain alkenoic acid or alkenoate of formula (III) R1OOC-(CH2)m-CH=CH-(CH2)y-H (III) where x
本申请涉及一种根据通式(IV)R1OOC-(CH2)m-CH2CH2-(CH2)y-COOR4(IV)制备二羧酸或二羧酸酯的方法,包括以下步骤:将通式(II)R1OOC-(CH2)m-CH=CH-(CH2)x-H(II)的烯酸或烯酸酯在存在烯烃交换催化剂的情况下进行交换反应,形成通式(III)R1OOC-(CH2)m-CH=CH-(CH2)y-H(III)的长链烯酸或烯酸酯,其中x
Selectivity in the Addition Reactions of Organometallic Reagents to Aziridine-2-carboxaldehydes: The Effects of Protecting Groups and Substitution Patterns
作者:Aman Kulshrestha、Jennifer M. Schomaker、Daniel Holmes、Richard J. Staples、James E. Jackson、Babak Borhan
DOI:10.1002/chem.201101168
日期:2011.10.24
especially the electronic character and conformational preferences of the nitrogen protecting groups. To help rationalize the observed stereochemical outcomes, conformational and electronic structural analyses of a series of model systems representing the various substitution patterns have been explored by density functional calculations at the B3LYP/6‐31G* level of theory with the SM8 solvation model to account
从优秀到卓越的立体选择性已发现在格氏和有机试剂和N的加成反应-保护的氮丙啶-2-羧醛。具体而言,苄基保护的顺式、叔丁氧羰基保护的反式获得了高顺式选择性和甲苯磺酰基保护的 2,3-二取代氮丙啶-2-甲醛。此外,还研究了环取代基、温度、溶剂和路易斯酸碱改性剂对速率和选择性的影响。添加的非对映异构偏好由底物氮丙啶的取代模式,尤其是氮保护基团的电子特征和构象偏好决定。为了帮助使观察到的立体化学结果合理化,已经通过 B3LYP/6-31G* 理论水平的密度泛函计算探索了一系列代表各种取代模式的模型系统的构象和电子结构分析,并使用 SM8 溶剂化模型来解释溶剂效应。
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