21383-02-8Relevant articles and documents
Chiral Ligands in Hypervalent Iodine Compounds: Synthesis and Structures of Binaphthyl-Based λ3-Iodanes
Zhang, Huaiyuan,Cormanich, Rodrigo A.,Wirth, Thomas
supporting information, (2021/12/22)
Several novel binaphthyl-based chiral hypervalent iodine(III) reagents have been prepared and structurally analysed. Various asymmetric oxidative reactions were applied to evaluate the reactivities and stereoselectivities of those reagents. Moderate to excellent yields were observed; however, very low stereoselectivities were obtained. NMR experiments indicated that these reagents are very easily hydrolysed in either chloroform or DMSO solvents leading to the limited stereoselectivities. It is concluded that the use of chiral ligands is an unsuccessful way to prepare efficient stereoselective iodine(III) reagents.
Role of free space and conformational control on photoproduct selectivity of optically pure α-alkyldeoxybenzoins within a water-soluble organic capsule
Kulasekharan, Revathy,Maddipatla, Murthy V. S. N.,Parthasarathy, Anand,Ramamurthy
, p. 942 - 949 (2013/04/10)
Optically pure α-alkyl deoxybenzoins resulting in products of Norrish Type I and Type II reactions upon excitation has been investigated within the octa acid (OA) capsule in water. The product distribution was different from that in an organic solvent and was also dependent on the length of the α-alkyl chain. Most importantly, a rearrangement product not formed in an organic solvent arising from the triplet radical pair generated by Norrish Type I reaction was formed, and its yield was dependent on the alkyl chain length. In an organic solvent, since the cage lifetime is shorter than the time required for intersystem crossing (ISC) of the triplet radical pair to the singlet radical pair the recombination with or without rearrangement of the primary radical pair (phenylacetyl and benzyl) does not occur. Recombination without rearrangement within the capsule as inferred from monitoring the racemization of the optically pure α-alkyl deoxybenzoins suggesting the capsule's stability for at least 10-8 s (the time required for ISC) is consistent with our previous photophysical studies that showed partial opening and closing of the capsule in the time range of microseconds.
Steric parameters in the Ir-catalyzed regio- and diastereoselective isomerization of primary allylic alcohols
Li, Houhua,Mazet, Clement
supporting information, p. 6170 - 6173 (2014/01/17)
The iridium-catalyzed diastereo- and regioselective isomerization of primary allylic alcohols using Crabtree's catalyst or sterically modified analogs is reported. The importance of the size of the substituents on either the substrates or the catalysts has been rationalized by linear free energy relationships.
Diastereoselective friedel-crafts alkylation of indoles with chiral α-phenyl benzylic cations. Asymmetric synthesis of anti-1,1,2- triarylalkanes
Chung, John Y. L.,Mancheno, Danny,Dormer, Peter G.,Variankaval, Narayan,Ball, Richard G.,Tsou, Nancy N.
supporting information; experimental part, p. 3037 - 3040 (2009/05/07)
(Chemical Equation Presented) The reactions of chiral benzyl carbocations bearing α-phenyl substituents with N-sulfonylated indoles afford 1,1,2-triarylalkanes with antiselectivities. This outcome is a reversal of facial diastereoselectivity relative to B
Et2Zn-mediated rearrangement of bromohydrins
Li, Lezhen,Cai, Peijie,Guo, Qingxiang,Xue, Song
, p. 3516 - 3522 (2008/09/20)
(Chemical Equation Presented) A simple and highly efficient method for the rearrangement of bromohydrins mediated by Et2Zn to synthesize carbonyl compounds was described. Various β-bromo alcohols were treated with 0.6 equiv of Et2Zn to form a zinc complex in CH 2Cl2 at room temperature for 2 h, followed by 1,2-migration to give the corresponding carbonyl compounds. This remarkable and clean rearrangement is general for acyclic and cyclic bromohydrins, and a variety of ring-expansive and -contractive carbonyl compounds were obtained in good to excellent yields according to the feature of the starting bromohydrins. The functional group tolerance of organozinc reagents in this reaction will be useful in organic synthesis. The scope and limitations of this rearrangement process were also investigated.
CHEMICAL COMPOUNDS
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Page 106, (2010/02/06)
Compounds of formula (I):wherein variable groups are as defined within; for use in the inhibition of 11betaHSD1 are described
Modification of Photochemical Reactivity by Cyclodextrin Complexation: Alteration of Photochemical Behavior via Restriction of Translational and Rotational Motions. Alkyldeoxybenzoins
Reddy, G. Dasaratha,Ramamurthy, V.
, p. 5521 - 5528 (2007/10/02)
The photochemical behavior of alkyldeoxybenzoins has been investigated in isotropic organic solvents, in aqueous cyclodextrin solutions, and when they are bound to cyclodextrin in the solid state.Norrish type I and type II reactions occur in these media and the product distributions resulting from these primary processes are dependent on the medium.While in organic solvents the type I and the type II products are obtained in equal amounts, in the aqueous cyclodextrin solution the type II products are formed in large excess.In the solid state the type II products constitute more than 90percent of the product distribution.Ratios of products resulting via elimination and cyclization from the type II 1,4-diradical are also altered by the host cyclodextrin.Conformational and super-cage effects have been invoked to rationalize the dramatic alteration of the photobehavior of alkyldeoxybenzoins by the cyclodextrin.
