1-Bromo-1-lithioethene: a practical reagent in organic synthesis.

doi:10.1021/JO051125V

Paper

1-Bromo-1-lithioethene: a practical reagent in organic synthesis.

Published Nov 5, 2005 · Yehor Y. Novikov, P. Sampson

The Journal of organic chemistry

Q2 SJR score

10

Citations

0

Influential Citations

Full textSemantic Scholar

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.

Study Snapshot

1-bromo-1-lithioethene is a reliable reagent for organic synthesis, offering high diastereoselectivity and low basicity at low temperatures, potentially due to its unique crystalline structure.

PopulationOlder adults (50-71 years)

Sample size24

MethodsObservational

OutcomesBody Mass Index projections

ResultsSocial networks mitigate obesity in older groups.

1-Bromo-1-lithioethene: a practical reagent in organic synthesis.

References

Citations