1370340-57-0Relevant articles and documents
Highly Selective Nucleophilic 4-Aryl-2,3-allenylation of Malonates?
Song, Shihua,Ma, Shengming
supporting information, p. 1233 - 1238 (2020/07/27)
Allenes are a class of very important compounds and the development of straightforward, efficient, and highly enantioselective synthetic strategies for allenes have attracted extensive interests. Along this line, it is well known that aryl-substituted allenes may be readily racemized, thus, difficult to prepare in high ee. Herein, an efficient palladium-catalyzed nucleophilic allenylation of malonates with racemic 4-aryl-2,3-butadienyl carbonates has been developed. The selectivity issue of mono- vs. bis-allenylation with 2-non-substituted malonates has been addressed. By utilizing (R)-(–)-DTBM-SEGPHOS (5,5'-bis[di(3,5-di-t-butyl-4-methoxyphenyl)phosphino]-4,4'-bi-1,3-benzodioxole) as a chiral ligand, various aryl-substituted allenes and bisallenes have been prepared with good to excellent yields with high chemoselectivity and enantioselectivity under mild reaction conditions. Au-catalyzed cycloisomerization and APK (allenic Pauson–Khand) reactions affording optically active mono- and bicyclic products have been demonstrated.
A direct synthesis of allenes by a traceless petasis reaction
Mundal, Devon A.,Lutz, Kelly E.,Thomson, Regan J.
, p. 5782 - 5785 (2012/05/07)
A one-pot synthesis of allenes by the 2-nitrobenzenesulfonylhydrazide- mediated coupling of hydroxyaldehydes or ketones with alkynyl trifluoroborate salts is reported. This mild process involves in situ formation of a sulfonylhydrazone that reacts with alkynyl trifluoroborates to generate a transient propargylic hydrazide species. Decomposition of this unstable hydrazide via an intermediate monoalkyldiazine produces the allene products through an alkene walk mechanism.
