15
votes
Accepted
Why does NOCl dissociate as +NO and Cl-?
Firstly, the correct comparison to make to determine which is more likely of $\ce{NO+}+\ce{Cl-}$ and $\ce{NO-}+\ce{Cl+}$ is the ionization potential vs. the electron affinity of the the two species. ...
- 3,090
7
votes
Accepted
Stereochemistry of nitrosyl chloride addition to an alkene
Syn or anti addition is difficult to resolve with propene because the final product admits rotation about the single bond. However, if the rotation is constrained or the relative positions of the ...
- 62.6k
6
votes
Can enamines be formed from α,β-unsaturated ketones?
Stork and Birnbaum have reported (Tetrahedron Lett. 1961, 10, 313) the formation of dienamine 2 from octalone 1. Alkylation with methyl iodide leads to α-alkylation of the dienamine. Buffer conditions ...
- 17.5k
5
votes
Stereochemistry of nitrosyl chloride addition to an alkene
The most important fact about this question is the stereochemistry of nitrosyl chloride $(\ce{NOCl})$ addition to an alkene. The OP has wondered whether it follows syn- or anti-addition.
The answer is ...
- 42.1k
5
votes
Cram's rule for nucleophilic addition to carbonyl groups
Cram's rule, proposed by Donald Cram in 1952,[1] was the earliest model proposed for rationalising the stereoselectivity of nucleophilic additions to carbonyl groups with α-stereocentres. The model ...
- 71.9k
4
votes
Isocyanides undergo addition reactions, but cyanides do not. Why?
Isocyanide can undergo addition reaction due to the fact that it is capable to attach both the electrophile and nucleophile in the same carbon atom while it is not achieved by cyanide. The negative ...
- 26.8k
3
votes
Accepted
What is the driving force for imine formation?
In practice, a drying agent is sometimes added to the reaction: I've used molecular sieves before, but a cursory database search brings up a few other options, e.g. magnesium sulfate, silica gel, or ...
- 71.9k
2
votes
Mechanism for cyclic enamine formation after N-Boc deprotection
Those conditions just give the amine. One you have an amine and an aldehyde or ketone, you should form an imine or iminium ion. Imines are relatively stable, but secondary amines, such as the one in ...
- 17.6k
2
votes
difference between elimination reactions and oxidation reactions
Whether the oxidation of an alochol or the reduction of a carbonyl group follows a certain mechanism depends on the reagents/conditions.
For example:
The sodium borohydride reduction of a ketone ...
- 43.2k
1
vote
Electrophilic addition to benzene
This is an electrophillic reaction. These reactions make cationic intermediates. There's never been a question about stabilizing intermediate carbanions in electrophillic reactions. Thus, you are ...
- 42.1k
1
vote
Carbocation Stability: Tertiary versus Secondary Benzyl for Hydrobromic Acid Addition
In the first instance, bromine will attach itself on the benzylic carbon as the benzylic carbocation formed in this case would be more stable than than the tertiary carbocation due to the mesomeric ...
- 122
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