Transition-metal-free synthesis of aryl 1-thioglycosides with arynes at room temperature

Yao Liu1, Xiao-Bing Yu1, Xiang-Mei Zhang1

  • 1National Engineering Research Center for Carbohydrate Synthesis, Jiangxi Normal University Nanchang 330022 P. R. China yannan@jxnu.edu.cn.

RSC Advances
|April 28, 2022
PubMed

Related Concept Videos

Preparation of 1° Amines: Gabriel Synthesis01:28

Preparation of 1° Amines: Gabriel Synthesis

Direct alkylation is not a suitable method for synthesizing amines because it produces polyalkylated products. Gabriel synthesis is the most preferred method to exclusively make primary amines. The method uses phthalimide, which contains a protected form of nitrogen that participates in alkylation only once to predominantly give primary amines.
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
3.8K
Preparation of Alkynes: Alkylation Reaction02:27

Preparation of Alkynes: Alkylation Reaction

Introduction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
10.7K
Preparation and Reactions of Thiols02:33

Preparation and Reactions of Thiols

Thiols are prepared using the hydrosulfide anion as a nucleophile in a nucleophilic substitution reaction with alkyl halides. For instance, bromobutane reacts with sodium hydrosulfide to give butanethiol.
6.7K
Acidity of 1-Alkynes02:42

Acidity of 1-Alkynes


The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.
10.1K
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN101:14

Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1

Treating arylamines with nitrous acid gives aryldiazonium salts that are effective substrates in nucleophilic aromatic substitution reactions. The diazonio group in these salts can be easily displaced by different nucleophiles, yielding a wide variety of substituted benzenes. The leaving group departs as nitrogen gas, and this easy elimination is the driving force for the substitution reaction.
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
2.2K
Reduction of Alkynes to trans-Alkenes: Sodium in Liquid Ammonia02:10

Reduction of Alkynes to trans-Alkenes: Sodium in Liquid Ammonia

Alkynes can be reduced to trans-alkenes using sodium or lithium in liquid ammonia. The reaction, known as dissolving metal reduction, proceeds with an anti addition of hydrogen across the carbon–carbon triple bond to form the trans product. Since ammonia exists as a gas (bp = −33°C) at room temperature, the reaction is carried out at low temperatures using a mixture of dry ice (sublimes at −78°C) and acetone. 
When dissolved in liquid ammonia, an alkali metal,...
9.7K