204334-97-4Relevant academic research and scientific papers
Effective 1,4-Asymmetric C-C/C-O Stereoinduction in Indium-Promoted Coupling Reactions of Aldehydes to Protected and Unprotected [1-(Bromomethyl)vinyl] Alkanols. the Status of Intramolecular Chelation within Functionalized Allylindium Reagents
Paquette, Leo A.,Bennett, George D.,Isaac, Methvin B.,Chhatriwalla, Adnan
, p. 1836 - 1845 (2007/10/03)
The stereochemistry of the coupling reactions of oxygen-substituted bromides 8-10 with isobutyraldehyde, benzaldehyde, and cyclohexanecarboxaldehyde in water is described. The examples involving the O-silylated derivatives 8 exhibit moderate anti stereoselectivity. In contrast, rather high (most often in excess of 80:20) syn diastereofacial bias is observed when hydroxy bromides 10 are involved. Consequently, stereocontrolled 1,4-asymmetric induction under aqueous conditions can be realized in either direction on demand. These results are considered to reflect the fact that the siloxy systems enter into C-C bond formation via conventional Felkin-Anh transition state arrangements. The crossover observed for the unprotected analogues is believed to be a consequence of the preferred adoption of chelated transition states, these interactions likely being fundamental to aqueous organometallic chemistry.
