- Palladium-complex-catalyzed regioselective Markovnikov addition reaction and dehydrogenative double phosphinylation to terminal alkynes with diphenylphosphine oxide
-
Palladium-1,2-bis(diphenylphosphino)ethane complex catalyzes regioselective Markovnikov addition of diphenylphosphine oxide to terminal alkynes in propionitrile, while the use of triarylphopshines, di(o-tolyl)phenylphosphine in particular, as the ligand l
- Dobashi, Naotomo,Fuse, Kouichiro,Hoshino, Takako,Kanada, Jun,Kashiwabara, Taigo,Kobata, Chihiro,Nune, Satish Kumar,Tanaka, Masato
-
-
Read Online
- A highly regioselective hydrophosphination of terminal alkynes with tetraphenyldiphosphine in the presence of palladium catalyst
-
A novel palladium-catalyzed hydrophosphination of alkynes with tetraphenyldiphosphine takes place regioselectively to provide vinylic phosphines, which undergo air-oxidation during workups, affording the corresponding vinylphosphine oxides in good yields.
- Nagata, Shoko,Kawaguchi, Shin-ichi,Matsumoto, Michiko,Kamiya, Ikuyo,Nomoto, Akihiro,Sonoda, Motohiro,Ogawa, Akiya
-
-
Read Online
- Transition metal-free and regioselective vinylation of phosphine oxides and: H -phosphinates with VBX reagents
-
A series of phosphine oxides and H-phosphinates were vinylated in the presence of the iodine(iii) reagents vinylbenziodoxolones (VBX), providing the corresponding alk-1-enyl phosphine oxides and alk-1-enyl phosphinates in good yields with complete chemo- and regioselectivity. The vinylation proceeds in open flask under mild and transition metal-free conditions.
- Castoldi, Laura,Rajkiewicz, Adam A.,Olofsson, Berit
-
p. 14389 - 14392
(2020/12/01)
-
- Hydrophosphorylation of Alkynes Catalyzed by Palladium: Generality and Mechanism
-
We carried out a comprehensive study on the generality, scope, limitations, and mechanism of the palladium-catalyzed hydrophosphorylation of alkynes with P(O)-H compounds (i.e., H-phosphonates, H-phosphinates, secondary phosphine oxides, and hypophosphinic acid). For H-phosphonates, Pd/dppp was the best catalyst. Both aromatic and aliphatic alkynes, with a variety of functional groups, were applicable to produce the Markovnikov adducts in high yields with high regioselectivity. Aromatic alkynes showed higher reactivity than aliphatic alkynes. Terminal alkynes reacted faster than internal alkynes. Sterically crowded H-phosphonates disfavored the addition. For H-phosphinates and secondary phosphine oxides, Pd/dppe/Ph2P(O)OH was the catalyst of choice, which led to highly regioselective formation of the Markovnikov adducts. By using Pd(PPh3)4 as the catalyst, hypophosphinic acid added to terminal alkynes to give the corresponding Markovnikov adducts. Phosphinic acids, phosphonic acid, and its monoester were not applicable to this palladium-catalyzed hydrophosphorylation. Mechanistic studies showed that, with a terminal alkyne, (RO)2P(O)H reacted, like a Br?nsted acid, to selectively generate the α-alkenylpalladium intermediate via hydropalladation. On the other hand, Ph(RO)P(O)H and Ph2P(O)H gave a mixture of α- and β-alkenylpalladium complexes. In the presence of Ph2P(O)OH, hydropalladation with this acid took place first to selectively generate the α-alkenylpalladium intermediate. A subsequent ligand exchange with a P(O)H compound gave the phosphorylpalladium intermediate which produced the Markovnikov adduct via reductive elimination. Related intermediates in the catalytic cycle were isolated and characterized.
- Chen, Tieqiao,Zhao, Chang-Qiu,Han, Li-Biao
-
supporting information
p. 3139 - 3155
(2018/03/08)
-
- Catalyst- and Oxidant-Free Desulfonative C?P Couplings for the Synthesis of Phosphine Oxides and Phosphonates
-
An efficient and practical approach towards phosphine oxides and phosphonates has been successfully developed through the desulfonative coupling of various sulfones with secondary phosphine oxides and phosphites. This protocol features simple experimental
- Guo, Hong-Mei,Zhou, Quan-Quan,Jiang, Xuan,Shi, De-Qing,Xiao, Wen-Jing
-
supporting information
p. 4141 - 4146
(2017/10/09)
-
- Markovnikov versus anti-Markovnikov Hydrophosphination: Divergent Reactivity Using an Iron(II) β-Diketiminate Pre-Catalyst
-
The ability to tune between different regioselectivities using a common pre-catalyst is an unusual yet highly desirable process. Here, we report the use of an iron(II) pre-catalyst that can be used to synthesize vinyl phosphines in a Markovnikov-selective
- King, Andrew K.,Gallagher, Kimberley J.,Mahon, Mary F.,Webster, Ruth L.
-
p. 9039 - 9043
(2017/07/11)
-
- Iridium-N,P-ligand-catalyzed enantioselective hydrogenation of diphenylvinylphosphine oxides and vinylphosphonates
-
Diphenylvinylphosphine oxides and di- and trisubstituted vinylphosphonates have been employed as substrates in iridium-catalyzed asymmetric hydrogenations. Complete conversions and excellent enantioselectivities (up to and above 99percent ee) were observe
- Cheruku, Pradeep,Paptchikhine, Alexander,Church, Tamara L.,Andersson, Pher G.
-
supporting information; experimental part
p. 8285 - 8289
(2009/12/02)
-
- A highly regioselective palladium-catalyzed hydrophosphination of alkynes using a diphosphine-hydrosilane binary system
-
(Chemical Equation Presented) A novel transition-metal-catalyzed hydrophosphination of terminal alkynes using a diphosphine-hydrosilane binary system takes place regioselectively to provide vinylic phosphines, which undergo air oxidation during workup, affording the corresponding vinylphosphine oxides in good yields. In this hydrophosphination, hydrosilanes act as a useful hydrogen source, and furthermore, small amounts of oxygen is required to accomplish the reaction efficiently.
- Kawaguchi, Shin-Ichi,Nagata, Shoko,Nomoto, Akihiro,Sonoda, Motohiro,Ogawa, Akiya
-
p. 7928 - 7933
(2008/12/22)
-
- Efficient and Selective Nickel-Catalyzed Addition of H-P(O) and H-S Bonds to Alkynes
-
The cheap nickel catalysts are more reactive than the corresponding noble metal catalysts in the catalytic additions of a variety of P(O)-H bonds and an S-H bond to alkynes, affording regio- and stereoselectively both the Markovnikov and the anti-Markovnikov adducts, respectively, in high yields. A related five-coordinate hydrido nickel complex in the catalysis is successfully isolated, which can react readily with an alkyne to give the addition products. Copyright
- Han, Li-Biao,Zhang, Chen,Yazawa, Hideaki,Shimada, Shigeru
-
p. 5080 - 5081
(2007/10/03)
-
- On the Reaction of 2-Pyrrolecarbaldehyde with Hetero-substituted Ethenes
-
3H-Pyrrolizines 1 have been obtained from reactions of 2-pyrrolecarbaldehyde with ethenylphosphonates 2 and the phosphane oxide 5, respectively, the ratio of products depending on the structure of the educts.On varying the reaction conditions a controlled synthesis of both isomers 1e/f was achieved.Pyrrolizines, formed in a reaction of 2-pyrrolecarbaldehyde with ethenyl phenyl sulfone (3), could not be isolated since the reaction proceeded to give more complex pyrrolizine derivatives and the cyclazine 11.A mechanism is proposed for this multistep reaction.N-Alkylatio n of 2-pyrrolecarbaldehyde with dihaloalkanes has been carried out using phase transfer catalysis.
- Flitsch, Wilhelm,Lubisch, Wilfried
-
p. 1424 - 1435
(2007/10/02)
-
- An Improved Synthesis of Cyclazines from 3H-Pyrrolizines
-
The reaction of 3H-pyrrolizines 3 with vinamidinium salts 4 provides a new and generally applicable route to cyclazines 5.Pyrrolizinefulvenes are intermediates of this reaction as shown using 3f as an example. - Cyclopentacyclazines 11 were prepared from the hitherto unknown 3H-pyrrolizines 3b, c, d and the pyrrolizine esters 3e, f with the cyclopentadiene iminium salt 10 under conditions which have been described previously.Additional evidence for a close similarity between cyclazines 11 and the corresponding azulenes has been obtained from the UV spectra of 11.
- Batroff, Volker,Flitsch, Wilhelm,Leaver, Derek,Skinner, David
-
p. 1649 - 1658
(2007/10/02)
-
- ENEPHOSPHINILATION
-
A general method is described for the formation of vinylphosphines from arylsulfonylhydrazones.Oxidation of the resulting vinylphosphines yields phosphine oxides.
- Mislankar, Dattatraya G.,Mugrage, Ben,Darling, S. D.
-
p. 4619 - 4622
(2007/10/02)
-