2,2,6,6-Tetramethylpiperidine or TMP or HTMP is a clear liquid with an amine odor. This amine

Amine

Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...

 is used in chemistry

Chemistry

Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....

 as a hindered

Steric effects

Steric effects arise from the fact that each atom within a molecule occupies a certain amount of space. If atoms are brought too close together, there is an associated cost in energy due to overlapping electron clouds , and this may affect the molecule's preferred shape and reactivity.-Steric...

 base

Base (chemistry)

For the term in genetics, see base A base in chemistry is a substance that can accept hydrogen ions or more generally, donate electron pairs. A soluble base is referred to as an alkali if it contains and releases hydroxide ions quantitatively...

 (hindered amine

Hindered amine

Hindered amines are chemical compounds containing an amine functional group surrounded by a crowded steric environment. They have uses such as gas scrubbing, as stabilizers against light-induced polymer degradation, and as reagents for organic synthesis....

) because it can dissolve in organic solvents unlike ordinary bases such as potassium hydroxide

Potassium hydroxide

Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...

.

There are many ways to synthesise TMP. One recent method starts with a conjugate addition reaction of ammonia

Ammonia

Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

 to phorone

Phorone

Phorone, or diisopropylidene acetone, is a yellow crystalline substance with a geranium odor. It is a self-condensation product of acetone. It can also be obtained from certain camphor compounds.combustible when exposed to heat or flame...

. The intermediate triacetone amine

Triacetone amine

Triacetone amine is the heterocycle that arises via the condensation of acetone and ammonia according to the following equation:It is used to prepare the hindered amine 2,2,6,6-tetramethylpiperidine, CH2[CH2C2]2NH....

 is then reduced in a Wolff-Kishner reaction.

TMP is the starting material for an even stronger base lithium tetramethylpiperidide

Lithium tetramethylpiperidide

Lithium tetramethylpiperidide or LiTMP is an organic base and a non-nucleophilic base. It is traditionally synthesised from 2,2,6,6-tetramethylpiperidine and n-butyllithium at -78 °C, but recent reports show this reaction is sluggish and is better formed at 0 °C. The compound is stable in a...

 and the radical species TEMPO

TEMPO

oxyl, or oxidanyl or TEMPO is a chemical compound with the formula 32NO . This heterocycle is a red-orange, sublimable solid. As a stable radical, it has applications throughout chemistry and biochemistry. TEMPO was discovered by Lebedev and Kazarnowskii in 1960...

. Another non-nucleophilic base is N,N-diisopropylethylamine.

External links

• DataSheet I
• DataSheet II
• TMP applied in synthesis in Organic Syntheses
  Organic Syntheses
  Organic Syntheses is a scientific journal that since 1921 has provided the chemistry community with annual collections of detailed and checked procedures for the organic synthesis of organic compounds. The journal is peer reviewed...