23667-49-4Relevant academic research and scientific papers
Studies of the Metal Complexes of Cyclohexane Derivatives. VIII. Preparation and Properties of Platinum(II) and Cobalt(III) Complexes Containing (1R,2S,3S)- or (1S,2R,3R)-3-methyl-1,2-cyclohexanediamine
Saito, Reiko,Kidani, Yoshinori
, p. 3430 - 3436 (2007/10/02)
(1RS,2SR,3SR)-3-Methyl-1,2-cyclohexanediamine (3m-chxn), a methyl derivative of cis-1,2-cyclohexanediamine, was prepared and optically resolved.The absolute configurations of the enantiomers obtained were assigned on the basis of the Cotton effect of the trans-dichlorobis(diamine) complexes, each containing active 3m-chxn.The complexes of the 3)2L>2+, 2+, and 3>3+ types (en=1,2-ethanediamine, L=R,S,S- or S,R,R-3m-chxn) were also synthesized and characterized on the basis of their absorption, CD, and 13C NMR spectra.It has been found that the chelate rings adopted by R,S,S- and S,R,R-3m-chxn predominantly take δ and λ conformations respectively, because of the preferred equatorial orientation of the C2-C3 bond of the cyclohexane ring.The four diastereomers of 3>3+ were chromatographically isolated and assigned to fac-Λ(lel3), mer-Λ(lel3), fac-Δ(ob3), and mer-Δ(ob3).
The Diels-Alder Route to Allylsilanes from 1-Trimethylsilylbutadienes
Carter, Martin J.,Fleming, Ian,Percival, Alan
, p. 2415 - 2434 (2007/10/02)
The synthesis and Diels-Alder reactions of 1-trimethylsilylbutadiene (3) and its 3-methyl (17), 3-trimethylsilyloxy (20), 4-methyl (4), and 4-trimethylsilyl (6) derivatives are reported.The silyl group reduces somewhat the rate of the Diels-Alder reactions, and has, if anything, a small 'ortho'-directing effect on the regioselectivity in the reactions of (3) with methyl acylate, methyl propiolate, citraconic anhydride, and 2,6-dimethylbenzoquinone.The other substituent in the dienes (17), (20), and (4) is therefore the major influence on the regioselectivity in the reactions of these dienes with methyl acrylate and methyl propiolate.The products of the Diels-Alder reactions of (3), (17), and (4) are allylsilanes, which undergo clean protodesilylation with acid, and, with the acid and ester derived from the maleic anhydride adduct of (3), undergo epoxidation and sulphenylation reactions giving an allyl alcohol (33) and an allyl sulphide (37), respectively.The adducts from (20) can be hydrolysed to β-silylketones, which can be converted into enones by bromination. 1-Pentamethyldisilylbutadiene (15) is no more reactive and no more regioselective than (3).The 'ortho'-adduct (42) from the reaction of (3) and methyl propiolate aromatises with DDQ to give methyl m-trimethylsilylbenzoate (53) in high yield, in a reaction involving rearrangement of the silyl group, even though a direct dehydrogenation is an available pathway.
