51219-99-9Relevant academic research and scientific papers
One-Pot Synthesis of α,β-Unsaturated Esters, Ketones, and Nitriles from Alcohols and Phosphonium Salts
Ding, Weijie,Hu, Juan,Jin, Huile,Yu, Xiaochun,Wang, Shun
, p. 107 - 118 (2017/09/28)
A general method for the synthesis of α,β-unsaturated esters, ketones, and nitriles is successfully achieved by a one-pot copper-catalyzed oxidation with O 2 in air as oxidant. The solvent mixture of acetonitrile and formamide (1:1) is optimized to ensure the oxidation of alcohols, deprotonation of phosphonium salt, and Wittig reaction occur efficiently in one pot. A broad range of substrates has been explored for this process, including three electron-withdrawing group (CO 2 Et, COPh, CN) functionalized phosphonium salts. They reacted not only with benzylic and heteroaromatic alcohols, but also with aliphatic alcohols, forming the corresponding α,β-unsaturated esters, ketones, and nitriles in moderate to excellent yields.
Photocatalytic E → Z isomerization of polarized alkenes inspired by the visual cycle: Mechanistic dichotomy and origin of selectivity
Metternich, Jan B.,Artiukhin, Denis G.,Holland, Mareike C.,Von Bremen-Kuhne, Maximilian,Neugebauer, Johannes,Gilmour, Ryan
, p. 9955 - 9977 (2018/05/31)
Iteratively executed with exquisite spatial and temporal control, the selective isomerization of polarized alkenes underpins a plethora of complex biological processes ranging from natural product biosynthesis through to the mammalian visual cycle. However, nature's proficiency conceals the inherent difficulties in replicating this contrathermodynamic transformation in the laboratory. Recently, we disclosed the first highly Z-selective isomerization of polarized alkenes, employing the cinnamoyl chromophore as a retinal surrogate under UV-irradiation (402 nm) with (-)-riboflavin (Vitamin B2) as an inexpensive, organic photocatalyst (J. Am. Chem. Soc. 2015, 137, 11254-11257). This study was inspired by the propensity of crystalline (-)-riboflavin in the eyes of vertebrates to invert the intrinsic directionality of retinal isomerization. Herein, we extend this methodology to include a bioinspired, catalytic E → Z isomerization of α,β-unsaturated nitriles, thereby mimicking the intermediate Opsin-derived, protonated Schiff base in the visual cycle with simple polarized alkenes. Replacement of the iminium motif by a cyano group is well tolerated and gives an additional degree of versatility for postisomerization functionalization. Broad substrate scope is demonstrated (up to 99:1 Z:E) together with evidence of mechanistic dichotomy via both singlet and triplet energy transfer mechanisms. Kinetic studies, temperature dependent photostationary state correlations and investigation of substituent-based electronic perturbation of the alkene identified polarization combined with increased Z-isomer activation barriers as the selectivity governing factors in catalysis. This investigation demonstrates the importance of internal structural preorganization on photostationary composition and explicates the augmented Z-selectivity upon hydrogen-alkyl exchange at the β-position of the alkene.
Synthesis of olefins via a Wittig reaction mediated by triphenylarsine
Li, Lun,Stimac, Jared C.,Geary, Laina M.
, p. 1379 - 1381 (2017/03/17)
An arsine-mediated Wittig reaction for the synthesis of olefins is described. After heating triphenylarsine in the presence of an activated alkyl bromide for 30?min, the resulting arsonium salt condensed with aldehydes in as little as 5?min at room temperature, yielding the olefins in high yields. Aromatic, heteroaromatic, and alkyl aldehydes were all suitable substrates for this process.
Wittig Olefination Using Phosphonium Tetraphenylborate in the Absence of Additional Base
Huang, Wenhua,Zhao, Shuang-Hong,Dong, Guang-Ping
supporting information, p. 1802 - 1810 (2015/10/29)
The thermal decomposition of (substituted methyl)triphenylphosphonium tetraphenylborates, which can also be generated in situ from the corresponding phosphonium halide and NaBPh4, with an aldehyde affords olefins in 22-100% yields. This Wittig olefination does not need use additional base to form phosphorus ylide, and is highly tolerant of benzoic acid.
Direct oxidative coupling of benzenes with acrylonitriles to cinnamonitriles catalyzed by Pd(OAc)2/HPMoV/O2 system
Obora, Yasushi,Okabe, Yoshihisa,Ishii, Yasutaka
supporting information; experimental part, p. 4071 - 4073 (2010/11/04)
A facile direct synthesis of cinnamonitriles from acrylonitriles and benzenes is successfully achieved by using Pd(OAc)2/HPMoV/O 2 catalyst system via the direct C-H bond activation of benzenes using molecular oxygen as a terminal oxidant.
Indium(I) bromide-mediated coupling of dibromoacetonitrile with aldehydes followed by Boord elimination of bromine and oxygen of β-bromo alkoxides for preparation of 3-organyl-2-alkenenitriles
Peppe, Clovis,de Azevedo Mello, Paola,das Chagas, Rafael Pav?o
, p. 2335 - 2339 (2007/10/03)
The organoindium compound derived from indium monobromide and dibromoacetonitrile reacts with carbonyl compounds to afford the corresponding 2-bromo-2-cyano-indium(III) alkoxide. The action of a second equivalent of indium monobromide onto the alkoxides derived from aldehydes promotes the Boord elimination of the β-related oxygen and bromine atoms leading to 2-alkenenitriles.
Highly (Z)-selective synthesis of β-monosubstituted α,β-unsaturated cyanides using the peterson reaction
Kojima, Satoshi,Fukuzaki, Tomohide,Yamakawa, Atsushi,Murai, Yutaka
, p. 3917 - 3920 (2007/10/03)
(Chemical Equation Presented) The Peterson reaction between (t-BuO)Ph 2SiCH2CN and various aldehydes furnishes the corresponding β-monosubstituted α,β-unsaturated cyanides with high Z selectivity (Z:E = 92:8 to >98:2).
Highly Z-selective synthesis of disubstituted α, β-unsaturated cyanides and amides using 10-P-5 wittig type reagents
Kojima, Satoshi,Kawaguchi, Kazuhiro,Matsukawa, Shiro,Uchida, Keiichiro,Akiba, Kin-ya
, p. 170 - 171 (2007/10/03)
Phosphoranes (10-P-5) bearing cyanomethyl, acetamide, and N, N-dimethylacetamide groups were examined for Wittig type reactions. All three reacted to give the corresponding olefins. The reaction of the cyanomethyl reagent with aldehydes gave α, β-unsatura
Polymer-assisted Horner-Emmons olefination using PASSflow reactors: pure products without purification.
Solodenko, Wladimir,Kunz, Ulrich,Jas, Gerhard,Kirschning, Andreas
, p. 1833 - 1835 (2007/10/03)
A PASSflow protocol for the Horner-Emmons olefination of aldehydes using polymer-bound hydroxide ions in flowthrough reactors is presented which allows preparation of alkenes in very high yield with minimal purification.
STEREOSELECTIVE SYNTHESIS OF (2Z)-α,β-UNSATURATED NITRILES VIA TANDEM CONDENSATION-DESULFONYLATION OF α-CYANOSULFONES WITH ALDEHYDES
Huang, Xian,Pi, Jin-Hong,Huang, Zhi-Zhen
, p. 177 - 182 (2007/10/02)
In the presence of sodium telluride, α-cyanosulfones undergo tandem condensation-desulfonylation reaction with aromatic aldehydes to give (2Z)-α,β-unsaturated nitriles with good stereoselectivity.
