Highly enantioselective synthesis of linear beta-amino alcohols

Thomas-Xavier Métro1, Domingo Gomez Pardo, Janine Cossy

  • 1Laboratoire de Chimie Organique, Ecole Supérieure de Physique et de Chimie Industrielles de la ville de Paris (ESPCI ParisTech), CNRS, 10 rue Vauquelin, 75231 Paris Cedex 05, France.

Related Concept Videos

Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis01:07

Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis

Acetoacetic ester synthesis is a method to obtain ketones from alkyl halides and β-keto esters. The reaction occurs in the presence of an alkoxide base that abstracts the acidic proton of the β-keto esters. The step results in an enolate ion which is doubly stabilized. The enolate then reacts with an alkyl halide via the SN2 process to produce an alkylated ester intermediate with a new C–C bond. The hydrolysis of the intermediate, followed by acidification, results in an alkylated β-keto acid.
Preparation of Alcohols via Addition Reactions02:15

Preparation of Alcohols via Addition Reactions

Overview
The acid-catalyzed addition of water to the double bond of alkenes is a large-scale industrial method used to synthesize low-molecular-weight alcohols. An acidic atmosphere is required to allow the hydrogen in the water molecule to act as an electrophile and attack the double bond in an alkene. The addition of a proton to the double bond creates a carbocation intermediate. The proton preferentially bonds to the less substituted end of the double bond to create a more stable carbocation...
Alkylation of β-Diester Enolates: Malonic Ester Synthesis01:14

Alkylation of β-Diester Enolates: Malonic Ester Synthesis

Malonic ester synthesis is a method to obtain α substituted carboxylic acids from ꞵ-diesters such as diethyl malonate and alkyl halides.
Preparation of Alcohols via Substitution Reactions01:38

Preparation of Alcohols via Substitution Reactions

Overview
Alcohols can be synthesized from alkyl halides via nucleophilic substitution reactions. The highly polar carbon-halogen bond in the substrate makes halide a good leaving group. The hydroxide ion or water can act as a nucleophile to take the place of halide and form an alcohol. The substitution reactions occur via two different reaction pathways, SN1 or SN2, depending on the nature of carbon attached to the halide.
Primary alcohols are synthesized from primary alkyl halides, and the...
Hydroboration-Oxidation of Alkenes03:08

Hydroboration-Oxidation of Alkenes

In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
Regioselective Formation of Enolates01:33

Regioselective Formation of Enolates

As depicted in the figure below, the unsymmetrical ketones can form two possible enolates: less substituted or more substituted enolates. Usually, the thermodynamic enolates are formed from the more substituted α-carbon atom, while the kinetic enolates are formed faster by deprotonation from the less substituted position. The thermodynamic enolates have lower energy, so they are more stable. But the energy required to form kinetic enolates is less.