Related Experiment Video
Updated: Aug 14, 2026

A Protocol for Safe Lithiation Reactions Using Organolithium Reagents
Published on: November 12, 2016
1-Bromo-1-lithioethene: a practical reagent in organic synthesis
Yehor Y Novikov1, Paul Sampson
1Department of Chemistry, Kent State University, Kent, Ohio 44242, USA. yehor_novikov@yahoo.com
Abstract:
[reaction: see text] A reliable preparative scale synthesis of 1-bromo-1-lithioethene is reported. This reagent undergoes clean 1,2-addition with a range of aldehydes and ketones at -110 degrees C to afford the corresponding 2-bromo-1-alken-3-ols in moderate to excellent yield. Trapping with other electrophiles (acylsilanes, chlorosilanes, tributyltin chloride, iodine) cleanly provides practically useful yields of various 1-substituted 1-bromoethene products. Unexpectedly high diastereoselectivities were observed during the addition of 1-bromo-1-lithioethene to alpha-siloxy aldehydes (typically 10:1, Felkin-Ahn control) and protected ketopyranose and ketofuranose sugars (> or = 10:1, addition from the less-hindered face). The title organolithium reagent possesses relatively low basicity at low temperature, and is compatible with a variety of common protecting groups. We believe that these unusual properties of 1-bromo-1-lithioethene may originate from the specific crystalline structure of the reagent in which lithium is coordinatively saturated and thus unavailable for chelation.
More Related Videos
09:45Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
07:50Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
Related Concept Videos
Radical Substitution: Allylic Bromination
Halogenation of Alkenes
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Formation of Halohydrin from Alkenes
α-Bromination of Carboxylic Acids: Hell–Volhard–Zelinski Reaction
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Regioselectivity of Electrophilic Additions-Peroxide Effect