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Sodium hydride is the chemical compound with the empirical formula Na H.This alkali metal hydride is primarily used as a strong yet combustible base in organic synthesis.NaH is a saline (salt-like) hydride, composed of Na + and H − ions, in contrast to molecular hydrides such as borane, silane, germane, ammonia, and methane.
As the name suggests, a non-nucleophilic base is a sterically hindered organic base that is a poor nucleophile.Normal bases are also nucleophiles, but often chemists seek the proton-removing ability of a base without any other functions.
Deprotonation (or dehydronation) is the removal (transfer) of a proton (or hydron, or hydrogen cation), (H +) from a Brønsted–Lowry acid in an acid–base reaction. [ 1 ] [ 2 ] The species formed is the conjugate base of that acid.
To deprotonation of phosphonium salts, generating Wittig reagents. NaHMDS deprotonates compounds containing weakly acidic O–H, S–H, and N–H bonds. These include cyanohydrins and thiols. [5] NaHMDS converts alkyl halides to amines in a two step process that begins with N-alkylation followed by hydrolysis of the N–Si bonds:
The alkylphosphonium salt is deprotonated with a strong base such as n-butyllithium: [Ph 3 P + CH 2 R]X − + C 4 H 9 Li → Ph 3 P=CHR + LiX + C 4 H 10. Besides n-butyllithium (n BuLi), other strong bases like sodium and potassium t-butoxide (t BuONa, t BuOK), lithium, sodium and potassium hexamethyldisilazide (LiHMDS, NaHMDS, KHDMS, where HDMS = N(SiMe 3) 2), or sodium hydride (NaH) are also ...
The Williamson ether reaction follows an S N 2 (bimolecular nucleophilic substitution) mechanism. In an S N 2 reaction mechanism there is a backside attack of an electrophile by a nucleophile and it occurs in a concerted mechanism (happens all at once).
If an alkoxide such as sodium ethoxide is used as base, deprotonation takes place only to the extent of about 0.1% because acetone is a weaker acid than ethanol (pK a = 16). If, however, a more powerful base such as sodium hydride (NaH) or lithium diisopropylamide ( LDA ) is used, a carbonyl compound can be completely converted into its enolate ...
1 Mechanism. 2 Double deprotonation of ethyl acetoacetate. 3 See also. 4 References. Toggle the table of contents. ... CH 3 C(O)CH 2 CO 2 Et + NaH → CH 3 C(O)CH ...