40339-21-7Relevant articles and documents
Generation of a geminal dicarbenoid of chromium: Formation of allenes from terminal alkenes in one-pot
Takai, Kazuhiko,Kokumai, Ryo,Toshikawa, Shota
, p. 1164 - 1166 (2002)
Treatment of CCl4 with 4 equiv of CrCl2 in THF generates a geminal dicarbenoid of chromium by reduction of two of the chlorine atoms of CCl4, and the dicarbenoid species selectively reacts with terminal olefins to give cyclopropylidene carbenoids, which readily decompose to allenes.
Addition of Chloroprene Grignards to Aromatic Aldehydes: Synthesis of Homoallenyl Alcohols
Geissler, Arne G. A.,Breit, Bernhard
supporting information, p. 2621 - 2625 (2021/04/12)
A general procedure for the one-pot synthesis of racemic homoallenyl alcohols from the corresponding aldehyde and chloroprene-derived Grignards is described. Employing bis[2-dimethylaminoethyl]ether (BDMAEE) as an additive at low temperatures shifts the selectivity of the chloroprene Grignard addition to aldehydes such that it is almost exclusive toward allene formation. In a set of follow-up experiments, simple and more elaborate methods for further derivatization have been demonstrated, allowing quick access to more complex structures.
Migratory Hydrogenation of Terminal Alkynes by Base/Cobalt Relay Catalysis
Liu, Bingxue,Liu, Qiang,Liu, Xufang
supporting information, p. 6750 - 6755 (2020/03/13)
Migratory functionalization of alkenes has emerged as a powerful strategy to achieve functionalization at a distal position to the original reactive site on a hydrocarbon chain. However, an analogous protocol for alkyne substrates is yet to be developed. Herein, a base and cobalt relay catalytic process for the selective synthesis of (Z)-2-alkenes and conjugated E alkenes by migratory hydrogenation of terminal alkynes is disclosed. Mechanistic studies support a relay catalytic process involving a sequential base-catalyzed isomerization of terminal alkynes and cobalt-catalyzed hydrogenation of either 2-alkynes or conjugated diene intermediates. Notably, this practical non-noble metal catalytic system enables efficient control of the chemo-, regio-, and stereoselectivity of this transformation.
