146330-81-6Relevant articles and documents
Z-Selective alkyne semi-hydrogenation catalysed by piano-stool N-heterocyclic carbene iron complexes
Johnson, Chloe,Albrecht, Martin
, p. 2779 - 2783 (2018/06/14)
NHC iron(ii) piano-stool complexes catalyse the selective semi-hydrogenation of alkynes to alkenes using silanes as reducing agents. Aromatic terminal alkynes are converted to styrenes without over-reduction to ethylbenzene derivatives. Furthermore, internal aryl alkynes afford cis-alkenes with excellent Z-selectivity.
Asymmetric allylic alkylation of acyclic allylic ethers with organolithium reagents
Pérez, Manuel,Fa?anás-Mastral, Martín,Hornillos, Valentín,Rudolph, Alena,Bos, Pieter H.,Harutyunyan, Syuzanna R.,Feringa, Ben L.
, p. 11880 - 11883 (2012/10/29)
A highly efficient, regio- and enantioselective CuI/ phosphoramidite-catalyzed asymmetric allylic alkylation of allyl ethers with organolithium reagents is reported (see scheme). The use of organolithium reagents is essential for this catalytic C-C bond formation due to their compatibility with different Lewis acids. The versatility of allylic ethers under the copper-catalyzed reaction conditions with organolithium reagents is demonstrated in the shortest synthesis of (S)-Arundic acid. Copyright
Origin of the "β-oxygen effect" in the Barton deoxygenation reaction
Crich, David,Beckwith, Athelstan L. J.,Chen, Chen,Yao, Qingwei,Davison, Ian G. E.,Longmore, Robert W.,De Parrodi, Cecilia Anaya,Quintero-Cortes, Leticia,Sandoval-Ramirez, Jésus
, p. 8757 - 8768 (2007/10/02)
Photolysis of O-neopentyl S-tributylstannyl dithiocarbonate with hexaphenyl distannane, and 4-methoxyacetophenone as sensitizer, results in crossover of the stannyl groups. The reaction of O-octyl O′-(2-butoxyethyl) thiocarbonate with tributyltin deuteride or tris(trimethylsilyl)silane and a radical initiator shows no significant preference for the cleavage of either C-O bond. Intermolecular competitions between O-octyl O′-phenyl thiocarbonate and O-(2-butoxyethyl) O′-phenyl thiocarbonate for a deficiency of stannane or silane also indicated no significant preference for reaction of the β-oxygen-substituted substrate, leading to the conclusion that in conformationally unrestricted systems there is no significant β-oxygen effect in the Barton deoxygenation reaction. Competition experiments between the cis- and trans-O-(4-phenylcyclohexyl) S-methyl dithiocarbonates and the cis- and trans-O-(2-phenyl1,3-dioxan-5-yl) S-methyl dithiocarbonates for reaction with tributylstannane reveal that in every case the heterocyclic system is more reactive. The cis-isomers of 4-phenylcyclohexyl S-methyl dithiocarbonate and O-(2-phenyl-1,3-dioxan-5-yl) 5-methyl dithiocarbonate, with their axial xanthates, are more reactive than the corresponding transisomers. Molecular mechanics calculations suggest that the greater reactivity of the cis-series with respect to the trans is due to the greater relief of strain on fragmentation.
