16766-97-5Relevant academic research and scientific papers
Base-dependent stereoselectivity in reactions of acyl ligand in phenylacetyliron complex (η5-C5H5)Fe(CO)(PPh3)(COCH2Ph)
Guo,Zamojski
, p. 1105 - 1108 (1992)
Alkylation of the anion 4 is only little stereoselective and leads to mixtures of stereoisomeric products 5A,B-9A,B. Proportion of stereoisomers depends strongly on the base employed. Condensation with acetaldehyde or benzeldehyde leads to four stereoisomeric products 11C-F and 12C-F, proportion of which depends also on the bases used. Decomplexation leads in the case of alkylated products to bromides 13, and in the case of aldol product 11 to bromohydrin 14 and epoxides 15 and 16.
Method for synthesizing alkyne through catalytic asymmetric cross coupling (by machine translation)
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Paragraph 0205-0212; 0222-0224, (2020/01/12)
The invention belongs to the field of, asymmetric synthesis, and discloses a method for catalyzing asymmetric cross- coupling to synthesize: an alkyne, and the L method comprises, the following steps, of A: preparing B a cuprous, salt and C a: ligand; preparing a catalyst; adding a base; reacting the compound with the compound with the compound; and reacting the compound with the compound. Of these, one of them, X is selected from the group consisting of, R halogens. 1 Optionally substituted heteroarylsulfonylcyanamide groups selected from the, group consisting, of optionally substituted, phenyl groups In-flight vehicle, R6 Trialkyl silyl groups or alkyl radicals, R2 Cycloalkyl radicals optionally substituted with an, optionally substituted alkyl, (CH radical2 )n R4 Multi,layer chain, n＝0-10,R saw blade4 A group selected, from, the group consisting of phenyl, alkenyl, aralkynyls, noonyloxy,and, noonylsulfonylsulfonylsulfonylsulfonylsulfonylsulfonylsulfonylsulfonylsulfonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylsulphonylphenyl disiloxy-radicals. R3 A ligand, selected from hydrogen or any of the functional groups, is selected from the group consisting of, hydrogen and any L other functional group. The method, R disclosed by the, A invention has the, advantages of good catalytic, R ’ effect, wide application range. and high catalytic efficiency, and the, method disclosed by the, invention has the. advantages of good catalytic effect, wide application range and high catalytic efficiency. (by machine translation)
HBr–DMPU: The First Aprotic Organic Solution of Hydrogen Bromide
Li, Zhou,Ebule, Rene,Kostyo, Jessica,Hammond, Gerald B.,Xu, Bo
supporting information, p. 12739 - 12743 (2017/09/25)
HBr and DMPU (1,3-dimethyl-3,4,5,6-tetrahydro-2-pyrimidinone) form a room-temperature-stable complex that provides a mild, effective, and selective hydrobrominating reagent toward alkynes, alkenes, and allenes. HBr–DMPU could also replace other halogenating reagents in the halo-Prins reaction, ether cleavage, and deoxy-bromination reactions.
Regioselective alkylation reactions of 2,4-diphenyl-3H-1-benzazepine give either 3-alkyl-3H-1-benzazepines or 1-alkyl-1H-1-benzazepines
Ko, Allen,Lam, Aaron,Li, Jeffrey,Greer, Edyta M.,Szalda, David J.,Karimi, Sasan,Subramaniam, Gopal,Ramig, Keith
, p. 4386 - 4389 (2014/07/22)
2,4-Diphenyl-3H-1-benzazepine is deprotonated with either LDA or KHMDS. The resulting anion is alkylated with alkyl halides or MeOTs, giving either products of alkylation at C3, or at N, or a mixture of both. The regioselectivity depends on the base, presence of the complexing agent HMPA, and the leaving group of the alkylating agent. Using MeI as alkylating agent gives exclusively the C3-methylated product, while using MeOTs gives exclusively the N-methylated product. The N-alkylated products show evidence of stereodynamic behavior in their NMR spectra.
Stereocontrolled α-alkylation of fully protected L-serine
Brunner, Martin,Saarenketo, Pauli,Straub, Thomas,Rissanen, Kari,Koskinen, Ari M. P.
, p. 3879 - 3883 (2007/10/03)
Diastereoselective alkylation of the (2S,4S) and (2R,4S) diastereomers of 3-tert-butyl 4-methyl 2-tert-butyl-1,3-oxazolidine-3,4-dicarboxylate (1a/b) is reported. Formation of both diastereomers of these oxazolidines was achieved by changing the order of protection steps, and their relative and absolute configurations were determined by NOESY spectroscopy. The use of the bulky ring substituent tBu together with Boc as the N-protecting group led to the exclusive formation of only one alkylated diastereomer. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Tricyclic compounds, their production and use
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, (2008/06/13)
A compound of the formula: wherein R1 is H or a substituent; m is 1-3; Ar is an aromatic group which may be substituted; X is a bond or a divalent straight-chain group having 1-6 atoms which may be substituted; Y is —S—, —O—, or —N(R2— (R2 is H or a substituent group), Z is —N= or —C(R3)= (R3 is H or a hydrocarbon group), ring A is a benzene ring; ring B is a 5- to 7-membered ring which may be substituted, or a salt thereof is useful for eliciting a prostaglandin I2 receptor agonistic effect.
Hydroalumination of alkenes by the LiAlH4*3AlBr3 system
Gorobets, E. V.,Shitikova, O. V.,Lomakina, S. I.,Tolstikov, G. A.,Kuchin, A. V.
, p. 1573 - 1578 (2007/10/02)
The hydroalumination of a series of alkenes and some fused aromatic hydrocarbons by the LiAlH4*3AlBr3 system in low-polar solvents was studied.Alkenes with mono-, di-, tri-, and tetraalkyl substituted, mono- and diaryl substituted double bonds and anthracene react at room temperature to give the corresponding dibromoaluminoalkanes in high yields.Benzylidenefluorene, tetraphenylethylene, naphthalene, and phenanthrene do not undergo hydroalumination under these conditions.Camphene, bicyclooct-2-ene, and norbornene afford the corresponding organoaluminum compounds with high stereoselectivity.Oxidation and halo- and acyldemetallation of the resulting alkyl- and arylalanes were carried out.
SYNTHESIS, -SIGMATROPIC REARRANGEMENT AND ELECTROPHILIC BEHAVIOR OF ANGULARLY ALKYLATED 2-CARBETHOXY-TRICYCLO2,6>DECADIENONES
Lange, J. H. M.,Klunder, A. J. H.,Zwanenburg, B.
, p. 1495 - 1508 (2007/10/02)
The angular alkylation of tricyclodecadienone ester 1 with alkyl halides is described.A considerably diminished thermal stability is observed for the angularly alkylated tricyclic esters 7.Even at ambient temperature they rapidly undergo an unusually facile Cope rearrangement to bridge ketones 8.Both steric and electronic effects are held responsible for this unique behavior of 7.In contrast to ester 1, 6-alkyl esters 7 do not generally undergo conjugate addition.Instead, bridge ketone addition products are formed which may arise either from initial 1,2-nucleophilic addition to the C5-ketone function in 7 followed by Cope rearrangement or from a stereoselective nucleophilic addition to the bridge ketone function in the Cope rearrangement compound 8.The remarkable stereoselectivity of the latter reaction is discussed in terms of Cieplak's model for the addition of nucleophiles to cyclic ketones.
ANGULAR ALKYLATION OF 2-CARBOETHOXYTRICYCLO2,6>DECADIENONE AND ITS IMPLICATIONS FOR THE SKELETAL INTEGRITY
Klunder, A. J. H.,Lange, J. H. M.,Zwanenburg, B.
, p. 3027 - 3030 (2007/10/02)
Alkylation of tricyclodecadienone ester 4 leads to alkyl enones 6 in excellent yields.Due to severe steric congestion, these enones 6 undergo an unusually rapid skeletal rearrangement to bridged ketones 7.
Evidence for a Reversible Electrophilic Step in Olefin Bromination. The Case of Stilbenes
Bellucci, Giuseppe,Chiappe, Cinzia,Marioni, Franco
, p. 515 - 522 (2007/10/02)
Bromonium-bromide ion couple intermediates have been generated by reacting erythro- and threo-2-bromo-1,2-diphenylethanol with gaseous HBr in 1,2-dichloroethane and in chloroform.It has been shown that in both solvents these intermediates mainly collapse to meso-1,2-dibromo-1,2-diphenylethane but also release Br2 to give trans-stilbene.The ratios of trans-stilbene to the meso dibromide obtained in all these reactions ranged between 9:91 and 22:78.The product distributions of the additions of HBr and Br2, both in the absence and in the presence of HBr, have also been determined. cis-Stilbene rapidly added HBr in both solvents, but in 1,2-dichloroethane isomerization to trans-stilbene also occurred to a large extent. trans-Stilbene mainly underwent oligo- or polymerization.The reactions of both olefins with Br2 were found to be not stereospecific.In the presence of HBr, the bromination of trans-stilbene became anti stereospecific, but in the case of cis-stilbene it maintained only a very modest stereoselectivity, and in chloroform HBr addition was predominant.The kinetics of bromination of both trans- and cis-stilbene in 1,2-dichloroethane were shown to follow very cleanly a third-order rate law (second order in Br2).However, the product analysis during the bromination of cis-stilbene showed that significant amounts of the trans olefin were always present at incomplete conversion.It has been shown that the latter olefin is formed by Br2-catalyzed isomerization of the starting cis olefin.All these results can be rationalized by assuming that the formation of bromonium-bromide or bromonium-tribromide ion pair intermediates in the discussed reactions is actually reversible.
