57123-34-9Relevant academic research and scientific papers
Radical dehydroxylative alkylation of tertiary alcohols by Ti catalysis
Xie, Hao,Guo, Jiandong,Wang, Yu-Quan,Wang, Ke,Guo, Peng,Su, Pei-Feng,Wang, Xiaotai,Shu, Xing-Zhong
supporting information, p. 16787 - 16794 (2020/11/09)
Deoxygenative radical C?C bond-forming reactions of alcohols are a long-standing challenge in synthetic chemistry, and the current methods rely on multistep procedures. Herein, we report a direct dehydroxylative radical alkylation reaction of tertiary alcohols. This new protocol shows the feasibility of generating tertiary carbon radicals from alcohols and offers an approach for the facile and precise construction of all-carbon quaternary centers. The reaction proceeds with a broad substrate scope of alcohols and activated alkenes. It can tolerate a wide range of electrophilic coupling partners, including allylic carboxylates, aryl and vinyl electrophiles, and primary alkyl chlorides/bromides, making the method complementary to the cross-coupling procedures. The method is highly selective for the alkylation of tertiary alcohols, leaving secondary/primary alcohols (benzyl alcohols included) and phenols intact. The synthetic utility of the method is highlighted by its 10-g-scale reaction and the late-stage modification of complex molecules. A combination of experiments and density functional theory calculations establishes a plausible mechanism implicating a tertiary carbon radical generated via Ti-catalyzed homolysis of the C?OH bond.
3-tert-Butyl-Substituted Cyclohexa-1,4-dienes as Isobutane Equivalents in the B(C6F5)3-Catalyzed Transfer Hydro-tert-Butylation of Alkenes
Keess, Sebastian,Oestreich, Martin
supporting information, p. 5925 - 5928 (2017/05/05)
Cyclohexa-1,4-dienes with a tert-butyl group at C3 are shown to function as isobutane equivalents when activated by the strong boron Lewis acid tris(pentafluorophenyl)borane. The hitherto unprecedented transfer hydro-tert-butylation from one unsaturated hydrocarbon to another is achieved with 1,1-diarylalkenes as substrates, thereby presenting itself as a new way of incorporating tertiary alkyl groups into carbon frameworks. Transient carbocation intermediates give rise to competing reaction pathways that could not be fully suppressed.
Titanocene-Catalyzed Regioselective Carbomagnesation of Alkenes and Dienes
Nii, Shinsuke,Terao, Jun,Kambe, Nobuaki
, p. 573 - 576 (2007/10/03)
A new method for regioselective carbomagnesation of alkenes and dienes has been developed by the use of a titanocene catalyst. This reaction proceeds efficiently at 0 °C in THF in the presence of Cp2TiCl 2 by the combined use of organic halides (R-X; R = alkyl, aryl and vinyl) and n-BuMgCl to afford benzyl, α-silylalkyl, or allyl Grignard reagents, which were trapped with various electrophiles. The present reaction involves (i) addition of carbon radicals toward alkenes or dienes in the carbon-carbon bond-forming step and (ii) transmetalation on Ti of benzyl-α-silylalkyl-, or allyltitanocene with n-BuMgCl in the carbon-magnesium bond-forming step. The scope and limitations of this reaction have also been examined.
The Reaction of 2,2,5,5-Tetramethyl-3,4-diphenylhexane with D2. Stereochemical Effects in a High-Temperature Reaction
Guthrie, Robert D.,Sharipov, Rustem V.,Ramakrishnan, Sreekumar,Shi, Buchang,Davis, Burton H.
, p. 4504 - 4509 (2007/10/02)
The thermolysis of 2,2,5,5-tetramethyl-3,4-diphenylhexane was carried out at temperatures above 300 deg C in the absence and presence of D2 (14 MPa).The presence of D2 results in a greatly increased yield of the major product, neopentylbenzene.However, at higher concentrations of starting material, up to 50percent of the neopentylbenzene formed avoids deuterium incorporation, an outcome belived to result partly from participation of the phenylneopentyl radical in radical disproportionation reactions.The meso-isomer of starting material produces a substantial yield of stilbene in both the absence and presence of D2.Under D2, 1,2-diphenylethane is produced, and it is belived that stilbene and other alkenes present serve as D atom traps producing radicals which then participate in termination by disproportionation.Remarkably, the d,l-diastereomer gives a different product distribution than the meso-isomer, giving very little stilbene or other products of tert-butyl group loss.However, both systems produce 1-phenyl-2-methyl-2-propene by methyl radical loss from the phenylneopentyl radical.The formation of such alkenes and the path to termination they provide is blamed for the absence of efficient kinetic chains involving D atoms.
Free Radical Reactions of 1,1-Diarylethylenes with t-Butylmercury Chloride
Russell, Glen A.,Khanna, Rajive K.,Guo, Deliang
, p. 632 - 634 (2007/10/02)
The photostimulated reactions of Bu(t)HgCl with 1,1-diarylethylenes yield different products for the aryl groups C6H5, p-O2NC6H4, or p-MeOC6H4 reflecting the donor or acceptor properties of Bu(t)CB2C(*)(Ar)2.
Configuration Determination of (R)-(-)-1,1,2-Triphenyl-3,3-dimethylbutane and the Stereochemistry of the Reaction of Benzhydryllithium with (R)-(+)-α-Phenylneopentyl Chloride
Bright, Danielle Angrand,Mathisen, Donald E.,Zieger, Herman E.
, p. 3521 - 3524 (2007/10/02)
A three-step synthesis of optically pure (R)-(-)-1,1,2-triphenyl-3,3-dimethylbutane from (R)-(-)-α-tert-butylphenylacetic acid has been accomplished.The synthesis of α-phenylneopentyl chloroformate from optically pure (R)-(+)-1-phenyl-2,2-dimethyl-1-propa
