関連する実験動画

Updated: Jul 22, 2026

Determination of the Gas-phase Acidities of Oligopeptides
11:00

Determination of the Gas-phase Acidities of Oligopeptides

Published on: June 24, 2013

O-選択性およびN-無保護のフォスフォラミジート法におけるフォスフィートトライエステル中間体によって媒介されるフォスフォリレーションの有用性

Akihiro Ohkubo1, Yusuke Ezawa, Kohji Seio

  • 1Contribution from the Department of Life Science, Tokyo Institute of Technology, Division of Bioscience and Biotechnology, Frontier Collaborative Research Center, 4259 Nagatsuta, Midoriku, Yokohama 226-8501, Japan.

Journal of the American Chemical Society
|September 2, 2004
PubMed
まとめ

新しい活性化フォスフィート法により,オリゴヌクレオチド合成における選択的O-フォスフォリレーションが可能になり,保護されていない核塩基との課題を克服します. この進歩は,より長いDNA鎖と改変されたオリゴヌクレオチドの効率的な合成を可能にします.

さらに関連する動画

Hydrolysis of a Ni-Schiff-Base Complex Using Conditions Suitable for Retention of Acid-labile Protecting Groups06:44

Hydrolysis of a Ni-Schiff-Base Complex Using Conditions Suitable for Retention of Acid-labile Protecting Groups

Published on: April 6, 2017

Regioselective O-Glycosylation of Nucleosides via the Temporary 2',3'-Diol Protection by a Boronic Ester for the Synthesis of Disaccharide Nucleosides08:46

Regioselective O-Glycosylation of Nucleosides via the Temporary 2',3'-Diol Protection by a Boronic Ester for the Synthesis of Disaccharide Nucleosides

Published on: July 26, 2018

関連する概念動画

Nucleophilic Substitution Reactions02:34

Nucleophilic Substitution Reactions

Historical perspective
In 1896, the German chemist Paul Walden discovered that he could interconvert pure enantiomeric (+) and (-) malic acids through a series of reactions. This conversion suggested the involvement of optical inversion during the substitution reaction. Further, in 1930, Sir Christopher Ingold described for the first time two different forms of nucleophilic substitution reactions, which are known as SN1 (nucleophilic substitution unimolecular) and SN2 (nucleophilic substitution...
Acid-Catalyzed Ring-Opening of Epoxides02:24

Acid-Catalyzed Ring-Opening of Epoxides

Epoxides that are three-membered ring systems are more reactive than other cyclic and acyclic ethers. The high reactivity of epoxides originates from the strain present in the ring. This ring strain acts as a driving force for epoxides to undergo ring-opening reactions either with halogen acids or weak nucleophiles in the presence of mild acid. The acid catalyst converts the epoxide oxygen, a poor leaving group, into an oxonium ion, a better leaving group, making the reaction feasible. The...
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview01:26

1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview

Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...
2° Amines to N-Nitrosamines: Reaction with NaNO201:20

2° Amines to N-Nitrosamines: Reaction with NaNO2

Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.
Protecting Groups for Aldehydes and Ketones: Introduction01:23

Protecting Groups for Aldehydes and Ketones: Introduction

Protecting groups are compounds that can bind to a specific functional group in the presence of other functional groups to protect them from undesired chemical reactions. These compounds can selectively bind to particular functional groups and advance chemoselective reactions in polyfunctional systems (Figure 1). After the functional group has served its purpose, it is removed by reacting it with specific compounds.
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism01:37

1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism

Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.