14597-42-3Relevant articles and documents
Nickon et al.
, p. 1711,1716 (1965)
Studer et al.
, p. 23 (1963)
Tsuda,M.,Schroepfer,G.J.
, p. 1290 (1979)
N-indolyltriethylborate: A useful reagent for synthesis of C3-quaternary indolenines
Lin, Aijun,Yang, Jiong,Hashim, Mohamed
supporting information, p. 1950 - 1953 (2013/06/04)
N-Indolyltriethylborate was found to be a useful reagent for dearomatizing C3-alkylation of 3-substituted indoles with both activated and nonactivated alkyl halides to give C3-quaternary indolenines, pyrroloindolines, furoindoline, and hexahydropyridoindoline under mild reaction conditions. The utility of these reagents was demonstrated in the syntheses of a pyrroloindoline-4- cholestene hybrid and debromoflustramine B.
Oxidation of Δ4- and δ5-steroids with hydrogen peroxide catalyzed by porphyrin complexes of MnIII and FeIII
Rebelo, Susana L. H.,Simoes, Mario M. Q.,M. Graca P. M. S. Neves,Silva, Artur M. S.,Cavaleiro, Jose A. S.,Peixoto, Andreia F.,Pereira, Mariette M.,Silva, Manuela R.,Paixao, Jose A.,Beja, Ana M.
, p. 4778 - 4787 (2007/10/03)
In this paper we describe a new environmentally friendly method to promote the stereoselective epoxidation of Δ4- and Δ5- steroids. Metalloporphyrins efficiently catalyze the epoxidation reactions of 17β-acetoxy-4-androstene (1), 4-cholestene (2) and 3β-acetoxy-5- cholestene (3) in the presence of H2O2 as oxygen donor. Modeling the molecular structure of the porphyrin as well as the central metal allows the control of the preferential formation of α- or β-epoxides. Porphyrins with bulky, electron-withdrawing groups in the ortho positions of the meso phenyls and with MnIII as the central metal ion, such as [Mn(TDCPP)Cl], gave preferentially the β-epoxide of Δ4- and Δ5-steroids. [Fe(TPFPP)Cl] catalyzes preferentially the α-epoxidation of Δ4-steroids and also increases the stereoselectivity for the α-epoxide in Δ5-steroids, similar to the results obtained with m-CPBA (m-chloroperbenzoic acid) as oxidant. The substrate structure strongly influences the chemoselectivity of the reactions. The X-ray structures of two main products were determined, and two-dimensional NMR techniques allowed the full assignment of 1H and 13C NMR resonances as well as the stereochemistry of these products. A mechanistic proposal involving oxo species for the β-approach and peroxy species for the α-approach is proposed. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Phosphine effects in the copper(I) hydride-catalyzed hydrogenation of ketones and regioselective 1,2-reduction of α,β-unsaturated ketones and aldehydes. Hydrogenation of decalin and steroidal ketones and enones
Chen, Jian-Xin,Daeuble, John F.,Stryker, Jeffrey M.
, p. 2789 - 2798 (2007/10/03)
The stereoselectivity and regioselectivity of the catalytic hydrogenation of ketones and α,β-unsaturated ketones and aldehydes using soluble copper(I) hydride catalysts have been investigated as a function of the ancillary phosphine ligand. While a relatively narrow range of aryldialkylphosphine ligands produce active hydrogenation catalysts, some ligands provide higher selectivity for 1,2-reduction of acyclic unsaturated carbonyl substrates than observed using the previously reported dimethylphenylphosphine-stabilized catalyst. The synthetic utility of this class of hydridic hydrogenation catalysts is illustrated by the hydrogenation of decalin and steroidal ketones and enones, the latter giving allylic alcohols with high selectivity. (C) 2000 Elsevier Science Ltd.
