Selective Rhodium-Catalyzed Hydroformylation of Terminal Arylalkynes and Conjugated Enynes to (Poly)enals Enabled by a π-Acceptor Biphosphoramidite Ligand
Selective Rhodium-Catalyzed Hydroformylation of Terminal Arylalkynes and Conjugated Enynes to (Poly)enals Enabled by a π-Acceptor Biphosphoramidite Ligand
The vinylideneruthenium(II) complexes bearing bulky and basic tertiary phosphine ligands, RuCl2(CCHPh)L2
(L = PPri3, PCy3), serve as good catalyst precursors for (Z)-selective cross-dimerization between arylacetylenes and silylacetylenes in the presence of N-methylpyrrolidine.
The new iridium(I)-guanidinate complex served as an efficient catalyst for phosphine-dependent selective cross-dimerization between silylacetylene and terminal alkyl- or arylacetylene. Especially, in case of cross-dimerization between silylacetylene and alkylacetylene, E/Z selectivity of resulting enynes could be controlled by changing phosphine.
<i>Z</i>-Selective (Cross-)Dimerization of Terminal Alkynes Catalyzed by an Iron Complex
作者:Orestes Rivada-Wheelaghan、Subrata Chakraborty、Linda J. W. Shimon、Yehoshoa Ben-David、David Milstein
DOI:10.1002/anie.201601382
日期:2016.6.6
Efficient iron‐catalyzed homocoupling of terminal alkynes and cross‐dimerization of aryl acetylenes with trimethylsilylacetylene is reported. The complex [Fe(H)(BH4)(iPr‐PNP)] (1) catalyzed the (cross‐)dimerization of alkynes at room temperature, with no need for a base or other additives, to give the corresponding dimerized products with Z selectivity in excellent yields (79–99 %).
The dialkylaluminum hydride-promoted reaction of 1-silylalk-3-en-1-ynes gave symmetrical 1,2,3,5-tetrasubstituted benzenes as single regiolsomers. The novel cyclodimerization via skeletal rearrangement can be rationalized by an unprecedented mechanism Involving sequential hydroalumination, alkene isomerization, carboalumination, carbon-carbon bond cleavage, and retro-hydroalumination.
Microwave irradiated Pd-catalyzed C(sp)–H activation and cross-coupling with styryltrifluoroborates
作者:Mohammad Al-Masum、Wejdan Shaban
DOI:10.1016/j.tetlet.2015.01.107
日期:2015.3
Effective catalytic effect of PdCl2(d(t)bpf) on the C-H activation of alkynes and its ability to overcome the limitations of styryltrifluoroborates in cross-coupling reactions by avoiding the effects of the C-X bond on starting materials is developed. (C) 2015 Elsevier Ltd. All rights reserved.