17976-80-6Relevant academic research and scientific papers
Straightforward Synthesis of Fluorinated Enals via Photocatalytic α-Perfluoroalkenylation of Aldehydes
Wulkesch, Christian,Czekelius, Constantin
, p. 7425 - 7438 (2021)
(Per)fluorinated substances represent an important compound class with regard to drug design and material chemistry. We found a mild, operationally simple, and inexpensive photocatalytic perfluoroalkenylation reaction giving tetrasubstituted, highly electron-deficient enals straight from aldehydes. This one-step reaction tolerates various functional groups and can be applied to a wide range of substrates giving the products in yields of 52-84%.
Cross-Selective Aza-Pinacol Coupling via Atom Transfer Catalysis
Nagib, David A.,Rafferty, Sean M.,Rutherford, Joy E.,Wang, Lu,Zhang, Lumin
supporting information, p. 5622 - 5628 (2021/05/07)
A cross-selective aza-pinacol coupling of aldehydes and imines has been developed to afford valuable β-amino alcohols. This strategy enables chemoselective conversion of aliphatic aldehydes to ketyl radicals, in the presence of more easily reduced imines and other functional groups. Upon carbonyl-specific activation by AcI, a photoinitiated Mn catalyst selectively reduces the resulting α-oxy iodide by an atom transfer mechanism. The ensuing ketyl radical selectively couples to imines, precluding homodimerization by a classical reductive approach. In this first example of reductive, ketyl coupling by atom transfer catalysis, Zn serves as a terminal reductant to facilitate Mn catalyst turnover. This new strategy also enables ketyl radical couplings to alkenes, alkynes, aldehydes, propellanes, and chiral imines.
Chemoselective Cleavage of Si-C(sp3) Bonds in Unactivated Tetraalkylsilanes Using Iodine Tris(trifluoroacetate)
Matsuoka, Keitaro,Komami, Narumi,Kojima, Masahiro,Mita, Tsuyoshi,Suzuki, Kimichi,Maeda, Satoshi,Yoshino, Tatsuhiko,Matsunaga, Shigeki
, p. 103 - 108 (2021/01/13)
Organosilanes are synthetically useful reagents and precursors in organic chemistry. However, the typical inertness of unactivated Si-C(sp3) bonds under conventional reaction conditions has hampered the application of simple tetraalkylsilanes in organic synthesis. Herein we report the chemoselective cleavage of Si-C(sp3) bonds of unactivated tetraalkylsilanes using iodine tris(trifluoroacetate). The reaction proceeds smoothly under mild conditions (-50 °C to room temperature) and tolerates various polar functional groups, thus enabling subsequent Tamao-Fleming oxidation to provide the corresponding alcohols. NMR experiments and density functional theory calculations on the reaction indicate that the transfer of alkyl groups from Si to the I(III) center and the formation of the Si-O bond proceed concertedly to afford an alkyl-λ3-iodane and silyl trifluoroacetate. The developed method enables the use of unactivated tetraalkylsilanes as highly stable synthetic precursors.
Use of a benzyl ether as a traceless hydrogen donor in the anti-Markovnikov hydrofunctionalization of alkenes with xanthates
Hayashi, Hirohito,Kaga, Atsushi,Wang, Bin,Gagosz, Fabien,Chiba, Shunsuke
, p. 7535 - 7538 (2018/07/13)
A new protocol for the anti-Markovnikov hydrofunctionalization of alkenyl alcohol O-Bn ethers was developed using xanthates as functionalizing agents in the presence of lauroyl peroxide as a radical initiator and a stoichiometric oxidant. The benzyl group serves as a traceless hydrogen donor in the remote radical hydrogen atom transfer event during the process.
A radical anti-Markovnikov addition of alkyl nitriles to simple alkenes via selective sp3 C-H bond functionalization
Li, Zejiang,Xiao, Yingxia,Liu, Zhong-Quan
supporting information, p. 9969 - 9971 (2015/06/22)
An efficient hydrocyanoalkylation of unactivated alkenes with alkyl nitriles was developed. Through this free-radical-initiated selective activation of the α-C(sp3)-H bond of acetonitriles, an anti-Markovnikov addition of an α-cyano C-centered radical to olefins has been achieved, which allows a facile and convenient access to functionalized nitriles in large scales.
Cerium(III) chloride-mediated reactions of sulfonamide dianions
Johnson II, David C.,Widlanski, Theodore S.
, p. 5300 - 5309 (2007/10/03)
Presented here is the first report on the ability of cerium(III) chloride to mediate high-yielding and, oftentimes, highly diastereoselective additions of N-benzyl-α, N-dilithio methanesulfonamide to aldehydes and ketones of biological importance. Smooth addition was effected to base-sensitive substrates such as Fmoc-protected alaninal, citral, 5-cholesten-3-one, uridine 5′-aldehyde, 3′-ketouridine, and 3′-ketothymidine. The reaction was chemoselective for aldehydes in the presence of nitriles. Acetoxy groups are labile and thus not suitable protecting groups for alcohols under these conditions. N-Benzyl-α, N-dilithio methanesulfonamide was found to be of sufficient basicity to cause enolate formation with sensitive substrates, such as 1-phenylacetone. However, the addition of cerium(III) chloride mediated the basicity of the dianion and suppressed enolate formation in these cases. Further, cerium(III) has general utility for the addition of various N-aliphatic/aromatic methanesulfonamide dianions to 3′-ketouridine.
Ate Complex from Diisobutylaluminum Hydride and n-Butyllithium as a Powerful and Selective Reducing Agent for the Reduction of Selected Organic Compounds Containing Various Functional Groups
Kim, Sunggak,Ahn, Kyo Han
, p. 1717 - 1724 (2007/10/02)
The "ate" complex generated from diisobutylaluminum hydride and n-butyllithium in an equimolar ratio either in tetrahydrofuran-hexane or in toluene-hexane was reacted with a series of selected organic compounds containing various functional groups in order to explore the reducing properties and to determine the synthetic utility of the reagent.The reagent is very effective for selective 1,2-reduction of both acyclic and cyclic enones.The reagent in tetrahydrofuran-hexane gives slightly better 1,2-selectivity than in toluene-hexane in the reduction of some acyclic enones, whereas the reagent in toluene-hexane gives better 1,2-selectivity in the reduction of conjugated cyclohexenones.Esters and lactones are completely reduced to the corresponding alcohols at room temperature, whereas they are reduced to the corresponding alcohols and aldehydes at -78 deg C even with an excess amount of the reagent.Partial reduction of the esters and the lactones to the corresponding aldehydes has not been observed.Acid chlorides are rapidly reduced to the corresponding alcohols with an excess amount of the reagent at -78 deg C, whereas they are reduced to a mixture of the alcohol, the aldehyde, and the unreacted acid chloride with a stoichiometric amount of the reagent at -78 deg C.Acid anhydrides are rapidly and quantitatively reduced to an equimolar mixture of the acid and the alcohol at -78 deg C.Carboxylic acids and primary and secondary amides are inert to the reagent at room temperature and are recovered unchanged..Tertiary amides are cleanly reduced to the aldehydes with a stoichiometric amount of the reagent either at 0 deg C or at room temperature, whereas they are inert to the reagent at -78 deg C, which permits the selective reduction of other reducible functional groups in the presence of the tertiary amide group at the latter temperature.The reagent rapidly reduces simple primary alkyl, benzyl, and allyl bromides but slowly primary alkyl chlorides and secondary alkyl bromides.Tertiary alkyl and aryl halides are essentially inert to the reagent, whereas trityl bromide and vinyl bromide are reduced at a reasonable rate.Epoxides are cleanly reduced to the corresponding alcohols.The opening of the epoxide ring with this reagent proceeds with excellent isomeric purity, yielding the more highly substituted alcohol almost exclusively.Nitriles are resistant to reduction and are only slowly converted to the corresponding aldehydes at room temperature.Disulfides are rapidly and quantitatively reduced to the corresponding thiols.Sulfoxides and sulfones are inert to the reagent and are recovered unchanged.Selective reductions of an ester in the presence of other reducible groups such as a bromide, a tertiary amide, and a nitrile are achieved with the reagent at -78 deg C by using a modified procedure.Furthermore, the reagent is capable of reducing selectively a ketone in the presence of an ester.
CHEMOSELECTIVE REDUCTION OF CARBOXYLIC ACIDS INTO ALCOHOLS USING N,N-DIMETHYLCHLOROMETHYLENIMINIUM CHLORIDE AND SODIUM BOROHYDRIDE
Fujisawa, Tamotsu,Mori, Toshiki,Sato, Toshio
, p. 835 - 838 (2007/10/02)
A new method for the direct conversion of carboxylic acids to alcohols using N,N-dimethylchloromethyleniminium chloride and sodium borohydride was established.This method fulfills the chemoselective reduction of carboxylic acids with a functional moiety such as halide, ester, nitrile, and olefin.
Potassium on Alumina as a Reagent for Reductive Decyanation of Alkylnitriles.
Savoia, Diego,Tagliavini, Emilio,Trombini, Claudio,Umani-Ronchi, Achille
, p. 3227 - 3229 (2007/10/02)
Highly dispersed potassium over neutral alumina (K/Al2O3), easily prepared by melting potassium over alumina in an inert atmosphere, is capable of effecting reductive cleavage of the cyano group in alkylnitriles in hexane at room temperature in 70-91percent yield.This decyanation method is applied in the key step of a novel synthesis of (Z)-9-dodecen-1-yl acetate, the sex pheromone of Paralobesia viteana.
