What does TsCl with pyridine do?
TsCl and MsCl: Two Reagents That Convert Hydroxyl Groups (OH) Into Good Leaving Groups. Treatment of an alcohol with TsCl or MsCl, usually in the presence of a weak base such as pyridine, results in the sulfonate esters. (The purpose of pyridine is to mop up any HCl that is formed during the course of the reaction.)
How do I remove TsCl?
Tosyl chloride is soluble in hexanes; thus, it can be extracted by washing with hexanes, but this method is limited to products that are immiscible with hexanes. Chromatography is widely used, but it is slow and costly in terms of materials and time.
Is tosyl chloride a good Nucleophile?
Reaction type: Nucleophilic Substitution (usually SN2) Alcohols can be converted into tosylates using tosyl chloride and a base to “mop-up” the HCl by-product. Tosylates are good substrates for substitution reactions, reacting with nucleophiles in much the same way as alkyl halides.
What is PY in Organic Chem?
Py. Pyridine; Solvent, base, catalyst.
What is the purpose of Tscl?
Tosyl chloride (TsCl) is usually used as an activating group for primary alcohols. Due to its relatively large volume and the lower reactivity of secondary and tertiary alcohols, it usually doesn’t come into them, being selective to primary alcohols in most of the cases.
Is triflate or tosylate a better leaving group?
Triflate (-SO2CF3) esters are much more reactive than tosylates or mesylates, since the triflate anion is a superb leaving group.
What happens when benzyl alcohol reacts with TsCl and Ki?
The addition of KI to the reaction mixture of benzyl alcohol and TsCl led to the formation of benzyl iodide in 49% yield (entry 9 in Table 1). The results could be rationalized by the following way. The reactions of benzyl alcohols with TsCl usually gave the corresponding tosylates initially.
How to prepare (s)-2-cyanobutane from pyridine?
Step one is reaction with TsCl (and pyridine typically) to give the tosylate with retention. Step 2 is reaction with NaCN to give the cyano compound (S)-2-cyanobutane with inversion.
Is hydroxyl a suitable leaving group for SN2 reaction?
Hydroxide is not a suitable leaving group for SN2 reaction. The hydroxyl must be converted into a better leaving group first, such as the tosylate above. That leaves the problem of how to synthesize (R)-2-cyanobutane (retention of configuration).
What is the mechanism of SN2 reaction with NaOH?
The addition of NaOH and the inversion of stereochem followed by “only” suggested again an SN2 mechanism. No E2 products; hydroxide isn’t basic enough to deprotonate an alkane to a significant extent. The transformation of the alcohol into a nitrile group with inversion of stereochemistry is SN2; attacked with a non-protic solvent for good measure.