90-87-9Relevant articles and documents
Two-way homologation of aliphatic aldehydes: Both one-carbon shortening and lengthening via the same intermediate
Yoo, Jae Won,Seo, Youngran,Park, Jong Beom,Kim, Young Gyu
, (2020/01/13)
Aliphatic aldehydes can be homologated to both one-carbon shorter and one-carbon longer homologous carbonyl compounds through the 2–4 steps of reactions via the same intermediates, β,γ-unsaturated α-nitrosulfones, prepared from the proline-catalyzed sequential reactions of several aliphatic aldehydes with phenylsulfonylnitromethane. While the oxidative cleavage of the key intermediates gave one-carbon less homologous carbonyl compounds, the reduction of the same key intermediates followed by an oxidation produced one-carbon more homologous carbonyl compounds.
Phosphine-ligated Ir(III)-complex as a bi-functional catalyst for one-pot tandem hydroformylation-acetalization
Liu, Huan,Liu, Lei,Guo, Wen-Di,Lu, Yong,Zhao, Xiao-Li,Liu, Ye
, p. 215 - 221 (2019/04/17)
The complexation of IrCl3?3H2O with the electron-deficient phosphines (L1-L6) respectively afforded a bi-functional catalyst possessing the dual functions of transition metal complex (IrIII-P) and IrIII-Lewis acid for tandem hydroformylation-acetalization of olefins. The best result was obtained over L5-based IrCl3?3H2O catalytic system which corresponded to 97% conversion of 1-hexene along with 92% selectivity to the target acetals free of any additive. The crystal structure of the novel IrIII-complex of IrIII-L4 indicated that the electron-deficient nature of the involved phosphine warranted Ir-center in +3 valence state without reduction, which served as the Lewis acid catalyst for the subsequent acetalization of the aldehydes as well. Moreover, as an ionic phosphine, L6-based IrCl3?3H2O system immobilized in RTIL of [Bmim]PF6 could be recycled for 6 runs without the obvious activity loss or metal leaching.
Phosphonium-based aminophosphines as bifunctional ligands for sequential catalysis of one-pot hydroformylation-acetalization of olefins
Wang, Peng,Liu, Huan,Li, Yong-Qi,Zhao, Xiao-Li,Lu, Yong,Liu, Ye
, p. 3854 - 3861 (2016/06/14)
A series of ionic phosphonium-based aminophosphines L1-L3 were prepared and fully characterized, in each of which the involved bifunctional moieties of the phosphine fragment and Lewis acidic phosphonium were linked together by stable chemical bonds and bridged by one N-atom. The molecular structure of the L2-ligated Rh-complex (Rh-L2) indicated that such bifunctionalities were well retained without incompatibility problems. Investigations on co-catalysis over L1-L3 showed that L3 exhibited the best sequential catalysis for both hydroformylation and acetalization. The phosphine fragment in L3 was responsible for hydroformylation together with the Rh-complex and the phosphonium acted as the Lewis acidic catalyst in charge of acetalization. The L3-Rh(acac)(CO)2 system also exhibited good generality to hydroformylation-acetalization of a wide range of olefins in different alcohols.
Hypoiodous acid-catalyzed regioselective geminal addition of methanol to vinylarenes: synthesis of anti-Markovnikov methyl acetals
Peraka, Swamy,Mameda, Naresh,Marri, Mahender Reddy,Kodumuri, Srujana,Chevella, Durgaiah,Sripadi, Prabhakar,Nama, Narender
, p. 73732 - 73736 (2015/09/15)
A novel metal-free, catalytic geminal dimethoxylation of vinylarenes based on in situ generated HOI species from iodide salt and oxone is reported. The preliminary mechanistic investigations suggest that the key factor for achieving the anti-Markovnikov regioselectivity is the semipinacol rearrangement of an iodo functionalized intermediate, which is confirmed by an isotope labeling experiment. In addition, the reaction involves the de-iodination of a co-iodo intermediate via its oxidation to hypervalent iodine species rather than a common iodide abstraction by electrophiles. The HRESI-MS studies support the conversion of monovalent iodine containing intermediates to trivalent iodine intermediates during the catalytic conversion of aromatic alkenes into the corresponding terminal acetals.
Selective hydroformylation-acetalization of various olefins using simple and efficient Rh-phosphinite complex catalyst
Khan, Shoeb R.,Bhanage, Bhalchandra M.
, p. 5998 - 6001 (2013/10/22)
A simple and efficient Rh-phosphinite complex catalyst was studied for the selective hydroformylation of various olefins. The influence of various reaction parameters including the effect of temperature, pressure, catalyst loading, time, and solvents was studied. The protocol was also applied for the synthesis of various acetals via tandem hydroformylation-acetalization of olefins in alcohols as solvents. High activity and selectivity for acetal formation was achieved in the absence of co-catalysts with admirable substrate to catalyst mole ratio (TON 2500). The developed protocol works for a wide range of olefins to synthesize corresponding aldehydes and acetals under optimized reaction conditions.
Highly effective tandem hydroformylation-acetalization of olefins using a long-life Bronsted acid-Rh bifunctional catalyst in ionic liquid-alcohol systems
Jin, Xin,Zhao, Kun,Cui, Feifei,Kong, Fangfang,Liu, Qiangqiang
, p. 3236 - 3242 (2013/11/06)
A robust and highly effective tandem hydroformylation-acetalization of olefins using a Bronsted acid-Rh bifunctional catalyst (ARBC) in ionic liquid-alcohol systems is reported. The key feature of the ARBC is its use of a zwitterionic phosphine ligand bearing an amino acid tag. This novel ARBC shows an excellent catalytic efficiency and a long service life without a significant drop in both the hydroformylation efficiency and the acetalization efficiency or Rh loss for more than seventeen cycles. We believe that the long-term high activity and acetal selectivity mainly benefit from the synergy between the acidic active site and the Rh active site on the ARBC and the highly effective immobilization and recycling of ARBC in ionic liquid-alcohol systems due to the strong affinity of ARBC for the ionic liquid.
A generalized approach for iron catalyzed chemo- and regioselective formation of anti-Markovnikov acetals from styrene derivatives
Chowdhury, Abhishek Dutta,Lahiri, Goutam Kumar
supporting information; experimental part, p. 3448 - 3450 (2012/05/20)
Fe(BF4)2·6H2O in the presence of pyridine-2,6-dicarboxylic acid and PhI(OAc)2 can efficiently catalyze the formation of chemoselective dialkyl acetals from styrene derivatives with anti-Markovnikov regioselectivity in good to high yields under mild and benign reaction conditions.
Method for the selective formation of dimethyl acetals in the presence of hydroxylamine
Mickelsen, Ky J.,Tajc, Chelsea M.,Greenwood, Kevin R.,Browder, Cindy C.
experimental part, p. 186 - 194 (2011/10/31)
An inexpensive and mild method for the formation of dimethyl acetals from the corresponding aldehydes is achieved using hydroxylamine and methanol under neutral conditions at room temperature. Notably, the reaction is selective for aldehydes in the presence of ketones, rendering this an example of a chemoselective acetalization. For saturated, sterically accessible aldehydes, catalytic amounts of hydroxylamine may be employed to attain the corresponding dimethyl acetal as the sole product in good to excellent yield. Unsaturated and hindered aldehydes required stoichiometric amounts of hydroxylamine but provided dimethyl acetals as the major product in typically excellent yield. In some cases, the corresponding oxime was also observed but may be separated from the acetal by flash column chromatography or distillation. The involvement of an intermediate oxime compound is postulated. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file. Taylor & Francis Group, LLC.
A new scandium metal organic framework built up from octadecasil zeolitic cages as heterogeneous catalyst
Gandara, Felipe,Gomez-Lor, Berta,Iglesias, Marta,Snejko, Natalia,Gutierrez-Puebla, Enrique,Monge, Angeles
supporting information; experimental part, p. 2393 - 2395 (2009/09/06)
Zeolitic cages of the AST type are found in the novel scandium-squarate MOF, and the joining of them gives rise to a new binodal network with a unique topology; this new material is an efficient heterogeneous Lewis acid catalyst. The Royal Society of Chemistry 2009.
Epoxide ring-opening and Meinwald rearrangement reactions of epoxides catalyzed by mesoporous aluminosilicates
Robinson, Mathew W. C.,Davies, A. Matthew,Buckle, Richard,Mabbett, Ian,Taylor, Stuart H.,Graham, Andrew E.
experimental part, p. 2559 - 2564 (2009/10/30)
Mesoporous aluminosilicates efficiently catalyze the ring-opening of epoxides to produce β-alkoxyalcohols in high yields under extremely mild reaction conditions. These materials also catalyze the corresponding Meinwald rearrangement in non-nucleophilic solvents to give aldehydes which can be trapped in situ to provide the corresponding acetals in an efficient tandem process. The Royal Society of Chemistry 2009.
