Is MeLi a strong base?
Methyllithium is both strongly basic and highly nucleophilic due to the partial negative charge on carbon and is therefore particularly reactive towards electron acceptors and proton donors. In contrast to n-BuLi, MeLi reacts only very slowly with THF at room temperature, and solutions in ether are indefinitely stable.
Is linh2 a strong base?
2Li + 2R 2NH → 2LiNR 2 + H. Lithium amides are very reactive compounds. Specifically, they are strong bases.
What is the pKa of LDA?
36
LDA is commonly formed by treating a cooled (0 to −78 °C) mixture of tetrahydrofuran and diisopropylamine with n-butyllithium. When dissociated, the diisopropylamide anion can become protonated to form diisopropylamine. Diisopropylamine has a pKa value of 36.
Is Khmds a strong base?
Potassium bis(trimethylsilyl)amide (commonly abbreviated as KHMDS, Potassium(K) HexaMethylDiSilazide) is the chemical compound with the formula ((CH3)3Si)2NK. It is a strong, non-nucleophilic base with an approximate pKa of 26 (compare to lithium diisopropylamide, at 36).
What is the pKa of CH3O?
At a pH well below the pKa, we say only the conjugate acid is stable. Thus, leaving groups are stable when the “effective pH” is well above the pKa of the leaving group’s conjugate acid. For example, CH3O– will not be a leaving group at neutral pH (7) because the pKa of CH3OH is 17.
What is the pKa of nah2?
Sodium hydride is a very strong base. The short answer is the pKa is about 35: Some useful pKa values.
Why is sodamide a good drying agent for ammonia?
It is the reagent of choice for the drying of ammonia (liquid or gaseous) and is also widely used as a strong base in organic chemistry, often in liquid ammonia solution. One of the main advantages to the use of sodamide is that it is an excellent base and rarely serves as a nucleophile.
What is the pKa of h20?
Since [H2O] in pure water is 55.5 M, Ka = 1.8 x 10E-16, or pKa = 15.7 .
Can LDA deprotonate Ester?
“LDA” is strong enough to completely deprotonate ketones, esters, or 1,3-dicarbonyls 6.
What is the pKa of LiTMP?
pKa Values of Common Bases. pKa37.1 lithium tetramethyl- piperidide (LiTMP) pKa35.7 lithium diisopropyl amide LDA pK 35 amide H. 3COH. pKa15-16 methoxide H3C OH. pK. a16 ethoxide H3C OH. pKa16.5 isopropoxide H. 3C OH H.
What is the real pKa of water?
What is the real pKa of water? Bookmark this question. Show activity on this post. What is the p K a of water? A simple google search yields the value 15.74, but this site and this paper say it’s 14.0. According to my understanding, the correct answer should be 14.0: Thus follows p K a = 14.
What is the pKa of lithium conjugate acid?
Its conjugate acid has a pKa of ~26, making it is less basic than other lithium bases, such as LDA (pKa of conjugate acid ~36), but it is more sterically hindered and hence less nucleophilic. It can be used to form various organolithium compounds, including acetylides or lithium enolates.
What is the pKa of protonated alcohol?
1. Protonated carbonyl pKa = ‐7 Other important pKa’s 2. Protonated alcohol or ether pKa = ‐2 to ‐3 H2 = 35 3. Carboxylic acid pKa = 4‐5 4. Ammonium ion pKa = 9‐10 5. Phenol pKa = 10 6. Thiol pKa = 10 7. Alcohol pKa = 16‐18 8. Water pKa = 15.7 9. Amide pKa = 18 10.