49639-05-6Relevant articles and documents
Silver-catalyzed decarboxylative radical allylation of α,α-difluoroarylacetic acids for the construction of CF2-allyl bonds
Wang, Pingyang,Du, Pengcheng,Sun, Qianqian,Zhang, Jianhua,Deng, Hongmei,Jiang, Haizhen
supporting information, p. 2023 - 2029 (2021/03/16)
An efficient silver-catalyzed method of decarboxylative radical allylation of α,α-difluoroarylacetic acids to build CF2-allyl bonds has been developed. Using allylsulfone as an allyl donor, α,α-difluorine substituted arylacetic acids bearing various functional groups are successfully allylated to access a series of 3-(α,α-difluorobenzyl)-1-propylene compounds in moderate to excellent yields in aqueous CH3CN solution under the mild conditions. Experimental studies disclosed that the α-fluorine substitution of arylacetic acid has a great influence on free radical activity and reactivity.
Ni-Catalyzed Reductive Allylation of α-Chloroboronates to Access Homoallylic Boronates
Lou, Yixian,Qiu, Jian,Yang, Kai,Zhang, Feng,Wang, Chenglan,Song, Qiuling
supporting information, p. 4564 - 4569 (2021/06/28)
The transition-metal-catalyzed allylation reaction is an efficient strategy for the construction of new carbon-carbon bonds alongside allyl or homoallylic functionalization. Herein we describe a Ni-catalyzed reductive allylation of α-chloroboronates to efficiently render the corresponding homoallylic boronates, which could be readily converted into valuable homoallylic alcohols or amines or 1,4-diboronates. This reaction features a broad substrate scope with good functional group compatibility that is complementary to the existing methods for the preparation of homoallylic boronates.
Palladium-catalyzed substitution of allylic alcohols with sulfinate salts: A synthesis of bicalutamide
Jhang, Yin-Jia,Chang, Chieh-Yu,Lin, Yu-Huan,Lee, Chein-Chung,Wu, Yen-Ku
supporting information, (2021/05/04)
A method is presented for the direct substitution of allylic alcohols with sodium arylsulfinates. The process involves a cooperative action of palladium catalysts, phenylboronic acid and titanium tetraisopropoxide. By taking advantage of this protocol, we achieved a concise synthesis of bicalutamide, an anti-androgen compound for treating prostate cancer.
Isomerisation of Vinyl Sulfones for the Stereoselective Synthesis of Vinyl Azides
Collins, Niall,Connon, Robert,Evans, Paul,Sánchez-Sanz, Goar
supporting information, p. 6228 - 6235 (2020/10/02)
Reported is the construction, and facile base-mediated conversation of ten differently substituted 3-azido E-vinyl sulfones (γ-azido-α,β-unsaturated sulfones) into their isomeric vinyl azide counterparts. The requisite 3-azido E-vinyl sulfones were prepared from 3-bromo E-vinyl sulfones, which in turn were accessed from allyl sulfones via a bromination-elimination sequence. In relation to this a one-pot azidation-isomerisation sequence was developed which enabled the direct formation of the vinyl azides from the corresponding 3-bromo E-vinyl sulfones. Similarly, a convenient one-pot Horner–Wadsworth–Emmons olefination-isomerisation approach was utilised in order to prepare some of the allylic sulfones used in this study. The vinyl azide forming process typically proceeded with high levels of Z-selectivity, although this was dependent on the vinyl sulfone substitution pattern. Thus, with either no substituent or a methyl group in the γ- or β-position, relative to the sulfone, good, to high levels of Z-selectivity (Z/E = 85:15 to ≥ 95:5) were obtained. However, incorporation of an α-sulfonyl methyl substituent led to an E-selective process (Z/E = 20:80). A non-bonding interaction between the azido group and the α-sulfonyl vinylic proton is proposed, which acts as a conformational control mechanism to help guide the stereochemical outcome.
Reciprocal-Activation Strategy for Allylic Sulfination with Unactivated Allylic Alcohols
Xie, Peizhong,Sun, Zuolian,Li, Shuangshuang,Cai, Xinying,Qiu, Ju,Fu, Weishan,Gao, Cuiqing,Wu, Shisheng,Yang, Xiaobo,Loh, Teck-Peng,Loh, Teck-Peng
supporting information, p. 4893 - 4897 (2020/06/24)
A reciprocal-activation strategy for allylic sulfination with unactivated allylic alcohols was developed. In this reaction, the hydrogen bond interaction between allylic alcohols and sulfinic acids allowed for reciprocal activation, which enabled a dehydrative cross-coupling process to occur under mild reaction conditions. This reaction worked in an environmentally friendly manner, yielding water as the only byproduct. A variety of allylic sulfones could be obtained in good to excellent yields with wide functional group tolerance. In gram scale reactions, allylic sulfones could be conveniently isolated in high yield by filtration.
Synthesis of 4,4-Difluoroalkenes by Coupling of α-Substituted α,α-Difluoromethyl Halides with Allyl Sulfones under Photoredox Catalyzed Conditions
Uno, Misae,Sumino, Shuhei,Fukuyama, Takahide,Matsuura, Makoto,Kuroki, Yoshichika,Kishikawa, Yosuke,Ryu, Ilhyong
, p. 9330 - 9338 (2019/08/12)
Photoredox-catalyzed allylation of α-gem-difluorinated organohalides with allyl sulfones proceeded smoothly under visible light irradiation to give 4,4-difluoroalkenes in good yields. In the presence of catalytic Ru(bpy)3Cl2, Hantzsch ester, and diisopropylethylamine, the reaction was complete within 2 h. Using the same methodology, three-component cascade reactions to give 6,6-difluoroalkenes were carried out successfully.
Synthesis of allyl sulfoxides from allylsilanes via silyl sulfinates
Stikute, Agnese,Peipi??, Vilnis,Turks, Maris
, p. 4578 - 4581 (2015/07/08)
Allylsilanes underwent sila-ene reaction with sulfur dioxide in the presence of Lewis acid catalysts. The obtained Vogel's silyl sulfinates were found to act as sulfinyl transfer agents in reactions with aryl, heteroaryl, alkyl, and allyl Grignard reagents proceeding with the expulsion of the trialkylsilyloxy group to give allyl sulfoxides in up to 83% yield. The nucleophilic attack of Grignard reagents was accelerated in toluene and in the presence of LiCl or ZnCl2 as Lewis acidic additives. The developed method allows the transformation of allylsilanes into allyl sulfoxides.
Allylsilanes in "tin-free" oximation, alkenylation, and allylation of alkyl halides
Rouquet, Guy,Robert, Frederic,Mereau, Raphael,Castet, Frederic,Landais, Yannick
, p. 13904 - 13911 (2012/01/15)
Tin-free oximation, vinylation, and allylation of alkyl halides have been developed by using allylsilanes as di-tin surrogates. Initiation of the radical process with a peroxide provides the silyl radical, which can abstract a halogen from the corresponding alkyl halide. The resulting carbon-centered radical then adds to various acceptors, including a sulfonyloxime, a vinylsulfone, and an allylsulfone, leading to formation of the desired products along with the corresponding allylsulfone resulting from the reaction of the PhSO2 radical with the allylsilane precursor. Better results were generally obtained with methallylsilane 1b than with 1a. This observation was rationalized by invoking the higher nucleophilicity of 1b and the faster β-fragmentation of the corresponding β-silyl radical intermediate. Calculation of the energy barrier for the β-fragmentation of a series of β-silyl radicals at the DFT level supported this hypothesis. Finally, a second version of these oximation and vinylation reactions, based on the utilization of 3-tris(trimethylsilyl)silylthiopropene, was devised, affording the desired oximes and olefins in reasonable yields. This strategy allowed the title reaction to be performed under milder conditions (AIBN, benzene, 80°C), as a result of the easier β-fragmentation of the C-S bond as compared with the C-Si bond.
Methylenecyclopropanes in elimination and addition reactions: Quantification of the effects of strain
Volta, Luca,Stirling, Charles J. M.
scheme or table, p. 1508 - 1522 (2010/03/24)
The effect of strain in 1,2-elimination reactions that form methylenecyclopropanes has been evaluated for a series of leaving groups. The worse the leaving group, the greater is the inhibitory effect of strain build-up, which reaches 50% of the excess enthalpy differential for the poorest leaving group studied. In nucleophilic addition to an electrophilic methylenecyclopropane, comparison of strained and unstrained systems shows that about 60% of the excess enthalpy differential promotes the reactivity of the strained system.
An expeditious entry to benzylic and allylic sulfones through byproduct-catalyzed reaction of alcohols with sulfinyl chlorides
Li, Hai-Hua,Dong, De-Jun,Jin, Yin-Huan,Tian, Shi-Kai
supporting information; experimental part, p. 9501 - 9504 (2010/03/04)
(Chemical Equation Presented) In the absence of external catalysts and additives, a broad range of benzylic and allylic alcohols react with various sulfinyl chlorides to afford structurally diversified benzylic and allylic sulfones in moderate to excellen
