119433-76-0Relevant articles and documents
NMR determination of the absolute configuration of cyclic chiral alkenes
Fukui,Fukushi,Tahara
, p. 325 - 328 (1999)
By the use of a new axially chiral reagent, 2'-methoxy-1,1'- binaphthalene-2-carbohydroximoyl chloride (MBCC), chiral cyclic alkenes were stereoselectively derivatized into 4,5-dihydroisoxazoles. NOEs were observed between the protons of the reagent moiety and those of the alkene moiety in cycloadducts. The absolute configuration of the original alkenes was unambiguously determined by the NOE correlation.
Two-step azidoalkenylation of terminal alkenes using iodomethyl sulfones
Lapointe, Guillaume,Millius, Nicolas,Renaud, Philippe
, (2019)
The radical azidoalkylation of alkenes that was initially developed with α-iodoesters and α-iodoketones was extended to other activated iodomethyl derivatives. By using iodomethyl aryl sulfones, the preparation of γ-azidosulfones was easily achieved. Faci
Methylenation for Aldehydes and Ketones Using 1-Methylbenzimidazol-2-yl Methyl Sulfone
Ando, Kaori,Oguchi, Mai,Kobayashi, Takahisa,Asano, Haruka,Uchida, Nariaki
, p. 9936 - 9943 (2020/09/04)
The methylenation reagent 1-methylbenzimidazol-2-yl methyl sulfone 2 reacts with various aldehydes and ketones in the presence of t-BuOK (room temperature, 1 h) in dimethylformamide to give the corresponding terminal alkenes generally in high yields. For sensitive substrates, the reaction is better carried out at low temperature using sodium hexamethyldisilazide in 1,2-dimethoxyethane. The byproduct is easily removed from the products, and the reaction conditions are mild and practical. Reagent 2 can be easily prepared from commercially available 2-mercaptobenzimidazole 5 in 95% yield without any expensive reagents.
Cationic nickel(II)-catalyzed hydrosilylation of alkenes: Role of p, n?type ligand scaffold on selectivity and reactivity
Hossain, Istiak,Schmidt, Joseph A.R.
supporting information, p. 3441 - 3451 (2020/10/09)
Seven structurally similar cationic nickel(II)?alkyl complexes were synthesized by using a series of P, N ligands, and their reactivity was explored in the hydrosilylation of alkenes. More electron-rich phosphines enhanced the overall reactivity of the transformation; in contrast, groups on the imine donor had little impact. Overall, these catalysts displayed reactivity and selectivity that was previously unknown or very rare in nickel-catalyzed hydrosilylation. In reactions with Ph2SiH2, 1,2-disubstituted vinylarenes showed complete benzylic selectivity for silane addition, whereas terminal selectivity was observed for 1,1-disubstituted alkenes. The related PhSiH3 led to exclusively Markovnikov selectivity for monosubstituted vinylarenes with no competing double addition observed. Mechanistic investigations supported the hypothesis that a Ni?H functions as the active species in this catalytic hydrosilylation, which in turn also showed catalytic competence for the silane redistribution reaction, especially with sterically unhindered silanes.
Branch-Selective Addition of Unactivated Olefins into Imines and Aldehydes
Matos, Jeishla L. M.,Vásquez-Céspedes, Suhelen,Gu, Jieyu,Oguma, Takuya,Shenvi, Ryan A.
supporting information, p. 16976 - 16981 (2019/01/04)
Radical hydrofunctionalization occurs with ease using metal-hydride hydrogen atom transfer (MHAT) catalysis to couple alkenes and competent radicalophilic electrophiles. Traditional two-electron electrophiles have remained unreactive. Herein we report the reductive coupling of electronically unbiased olefins with imines and aldehydes. Iron catalysis allows addition of alkyl-substituted olefins into imines through the intermediacy of free radicals, whereas a combination of catalytic Co(Salt-Bu,t-Bu) and chromium salts enables a branch-selective coupling of olefins and aldehydes through the formation of a putative alkyl chromium intermediate.
Practical Methylenation Reaction for Aldehydes and Ketones Using New Julia-Type Reagents
Ando, Kaori,Kobayashi, Takahisa,Uchida, Nariaki
supporting information, p. 2554 - 2557 (2015/05/27)
A new Julia-type methylenation reagent, 1-methyl-2-(methylsulfonyl)benzimidazole (1e), reacts with a variety of aldehydes and ketones in the presence of either NaHMDS (-55 °C to rt) or t-BuOK (rt, 1 h) in DMF to give the corresponding terminal alkenes in high yields. The byproducts are easily removed, and the reaction conditions are mild and practical.
Efficient and stereoselective nitration of mono- and disubstituted olefins with AgNO2 and TEMPO
Maity, Soham,Manna, Srimanta,Rana, Sujoy,Naveen, Togati,Mallick, Arijit,Maiti, Debabrata
supporting information, p. 3355 - 3358 (2013/04/10)
Nitroolefin is a common and versatile reagent. Its synthesis from olefin is generally limited by the formation of mixture of cis and trans compounds. Here we report that silver nitrite (AgNO2) along with TEMPO can promote the regio- and stereoselective nitration of a broad range of olefins. This work discloses a new and efficient approach wherein starting from olefin, nitroalkane radical formation and subsequent transformations lead to the desired nitroolefin in a stereoselective manner.
Development of the first menthane-based chiral bis(π-allylpalladium) catalysis: Asymmetric allylation of imines
Fernandes, Rodney A.,Chaudhari, Dipali A.
experimental part, p. 1945 - 1952 (2012/05/20)
A new ethylidene menthane-based chiral π-allylpalladium complex catalyzes the asymmetric allylation of various imines with allyltributylstannane and 1 equiv. of water to give chiral homoallylamines in good yields and enantioselectivities. The reaction was carried out essentially under neutral conditions and displayed a good transfer of chiral information from the menthane skeleton through the formation of a bis(π-allylpalladium) species. This is the first example of menthane-based chiral bis(π-allylpalladium) catalysis. A menthane-based chiral π-allylpalladium-catalyzed asymmetric allylation of various imines has been developed giving chiral homoallylamines in good yields and enantioselectivities. The reaction displays a good transfer of chiral information from the menthane skeleton through the formation of a bis(π-allylpalladium) complex. Copyright
Synthesis and characterization of a new enantiopure hydroxylated phosphine, its rhodium(I) and (III) complexes and their performance in catalytic carbonylation
Duran, Josep,Oliver, Daniel,Polo, Alfonso,Real, Julio,Benet-Buchholz, Jordi,Fontrodona, Xavier
, p. 2529 - 2538 (2007/10/03)
The enantiomerically pure hydroxylated phosphine (1S,2S,5R)-1-diphenylphosphinomethyl-2-isopropyl-5-methyl-cyclohexanol 3 was prepared in a two-step stereoselective process from the commercially available and low cost (-)-menthone. Reaction of this new li
Computer-Assisted Design of Chiral Boron Enolates: The Role of Ate Complexes in Determining Aldol Stereoselectivity.
Bernardi, Anna,Comotti, Angiolina,Gennari, Cesare,Hewkin, Cheryl T.,Goodman, Jonathan M.,et al.
, p. 1227 - 1242 (2007/10/02)
Transition-state modelling for the aldol reaction of chiral Z and E enol borinates (1 and 2, Scheme 1) bearing mixed ligands (L1=Ipc, L2=9) predicted higher enantioselectivities than those calculated and experimentally tested with C
