Iminium - Wikipedia
The general structure of an iminium cation. In organic chemistry, an iminium cation is a polyatomic ion with the general structure [R 1 R 2 C=NR 3 R 4] +. [1] They are common in synthetic chemistry and biology.
10.6: Imines - Chemistry LibreTexts
2022年7月20日 · The conversion of an iminium back to an aldehyde or ketone is a hydrolytic process (bonds are broken by a water molecule), and mechanistically is simply the reverse of iminiom formation: Hydrolysis of an iminium ion:
Imines – Properties, Formation, Reactions, and Mechanisms
2022年3月7日 · Elimination results in the conjugate acid of the imine, referred to as an iminium salt (or iminium ion). D eprotonation of the positively charged nitrogen (Step 6, break N-H) gives us the neutral imine .
19.8: Nucleophilic Addition of Amines- Imine and Enamine …
2024年9月30日 · Protonation of the carbinolamine oxygen by an acid catalyst then converts the –OH into a better leaving group (–OH 2 +), and E1-like loss of water produces an iminium ion. Loss of a proton from nitrogen gives the final product and regenerates the acid catalyst.
Imine and Enamine Formation - Chemistry LibreTexts
Step 4: The lone pair electrons on the nitrogen form the C=N double bond causing water to be eliminated. This forms an iminium ion. Step 5: Water (or a base) removes a hydrogen from an adjacent carbon to form an alkene bond.
Hydrolysis of imines to give ketones (or aldehydes)
Mechanism: Protonation of the imine nitrogen (Step 1, arrows A and B) results in the formation of the iminium ion, which undergoes 1,2-addition by water (Step 2, arrows C and D). Transfer of a proton (Step 3, arrows E and F) followed by 1,2 elimination of ammonia (Step 4, arrows G and H) lead to an oxonium ion, which is then deprotonated to ...
Iminium Ion - an overview | ScienceDirect Topics
Cyclization reactions of iminium ions, R 1 2 C NR 2 +, are a recurring theme in the assembly of cyclic nitrogenous compounds by both chemists and Nature. 1 The electron-deficient iminium ion is the nitrogen analog of an α-alkoxycarbenium (oxonium) ion or activated carbonyl group and as such is a fundamental electrophilic component of C C bond ...
Visible-light excitation of iminium ions enables the ... - Nature
2017年3月20日 · With the aim of selectively exciting the transient chiral iminium ion Ia, we conducted the explorative experiments detailed in Table 1 in CH 3 CN under irradiation by a single high-power...
Asymmetric catalytic formation of quaternary carbons by iminium ion ...
2016年4月13日 · This method appears to be the first application of iminium ion activation, a successful catalytic strategy for enantioselective polar chemistry, in the realm of radical reactivity.
Enamine and iminium ion–mediated organocatalysis . The Royal Swedish Academy of Sciences has decided to award Benjamin List and David W. C. MacMillan the Nobel Prize in Chemistry 2021, for the development of asymmetric organocatalysis. The Laureates’ seminal work in 2000 conceptualized the area of organocatalysis and stimulated its development.