Related Experiment Video
Updated: Jun 29, 2025

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Phosphine-Catalyzed [4 + 3] Annulation of β'-Acetoxy Allenoates with 1C,3N-Dinucleophiles: Access to Functionalized
Chunjie Ni1, Zhanhang Liang1,2, Xiaojuan Xu1,2
1School of Pharmacy, Yancheng Teachers University, Yancheng 224007, China.
Abstract:
A novel method for the synthesis of functionalized azepine derivatives has been developed through a phosphine-catalyzed [4 + 3] annulation of β'-acetoxy allenoates with benzimidazole-derived 1C,3N-dinucleophiles. This approach demonstrates high efficiency and yields ranging from moderate to excellent. The reaction exhibits a wide substrate scope under the optimized conditions. Furthermore, an initial exploration of the asymmetric variant of this reaction has been conducted, utilizing phosphine (R)-SITCP as the catalyst.
More Related Videos
10:42Preparation of N-2-alkoxyvinylsulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines
Published on: January 3, 2018
07:12Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Related Concept Videos
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
Preparation of Alkynes: Alkylation Reaction
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.
Preparation of 1° Amines: Azide Synthesis
Azide ions act as good nucleophiles and react with unhindered alkyl halides to form alkyl azides. Alkyl azides do not participate in further nucleophilic substitution reactions, thereby eliminating the chances of polyalkylated products. Alkyl azides are reduced by hydride-based reducing agents, like lithium aluminum...
Preparation of Alkynes: Dehydrohalogenation
Alkynes can be prepared by dehydrohalogenation of vicinal or geminal dihalides in the presence of a strong base like sodium amide in liquid ammonia. The reaction proceeds with the loss of two equivalents of hydrogen halide (HX) via two successive E2 elimination reactions.
Aldehydes and Ketones to Alkenes: Wittig Reaction Mechanism
The reaction begins with the nucleophilic addition between a phosphorus ylide and the carbonyl compound. Due to its carbanionic character, phosphorus ylide acts as a strong nucleophile and attacks the electrophilic carbonyl group. This generates a charge-separated dipolar intermediate called betaine. The negatively charged oxygen atom and...
Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview