112653-26-6Relevant academic research and scientific papers
Decarboxylative Conjunctive Cross-coupling of Vinyl Boronic Esters using Metallaphotoredox Catalysis
Aggarwal, Varinder K.,Duong, Vincent K.,Mega, Riccardo S.,Noble, Adam
, p. 4375 - 4379 (2020/02/11)
The synthesis of complex alkyl boronic esters through conjunctive cross-coupling of vinyl boronic esters with carboxylic acids and aryl iodides is described. The reaction proceeds under mild metallaphotoredox conditions and involves an unprecedented decarboxylative radical addition/cross-coupling cascade of vinyl boronic esters. Excellent functional-group tolerance is displayed, and application of a range of carboxylic acids, including secondary α-amino acids, and aryl iodides provides efficient access to highly functionalized alkyl boronic esters. The decarboxylative conjunctive cross-coupling was also applied to the synthesis of sedum alkaloids.
A rapid access to (±)-sedamine and some original N -benzyl unsaturated analogues
Boussonniere, Anne,Ranaivondrambola, Tsiresy,Lebreton, Jacques,Mathe-Allainmat, Monique
experimental part, p. 2456 - 2462 (2010/09/04)
Reduction of N-alkyl-2-(2-hydroxy-2-phenylethyl)pyridinium salts using excess of sodium triacetoxyborohydride afforded exclusively the corresponding tetrahydropyridine derivative bearing a piperidine ring with a double bond in the 3,4-position. Furthermore, under these conditions, syn-1,3-amino alcohols were obtained in good yield and diastereoselectivity. Georg Thieme Verlag Stuttgart · New York.
Asymmetric synthesis of Sedum alkaloids via lithium amide conjugate addition
Davies, Stephen G.,Fletcher, Ai M.,Roberts, Paul M.,Smith, Andrew D.
experimental part, p. 10192 - 10213 (2010/02/28)
Conjugate addition of lithium (R)-N-allyl-N-(α-methylbenzyl)amide or lithium (R)-N-but-3-enyl-N-(α-methylbenzyl)amide to an alkyl hexa-2,4-dienoate or alkyl hepta-2,6-dienoate, followed by ring-closing metathesis of the olefin functionalities within the resultant β-amino ester, generates a range of diastereoisomerically pure azacycles in good yield. These homochiral templates are readily transformed to a range of piperidine alkaloids of the Sedum family, and the corresponding five-, seven- and eight-membered ring homologues.
Studies on the Eschenmoser coupling reaction and insights on its mechanism. Application in the synthesis of Norallosedamine and other alkaloids
Neto, Brenno A.D.,Lapis, Alexandre A.M.,Bernd, Alinne B.,Russowsky, Dennis
experimental part, p. 2484 - 2496 (2009/08/07)
The conditions of the Eschenmoser coupling reaction were studied. The formation of the α-thioiminium ion was achieved faster in the presence of an additive (NaI) and dry chloroform as the preferred solvent. The developed conditions were used for the second part of the reaction (the sulfur extrusion itself). The present protocol avoids the formation of byproducts, which were previously described as a major drawback to be overcome. Electrospray ionization tandem mass spectrometry was used to characterize some aspects (intermediates) of the first step of the reaction mechanism. Some reduction conditions were properly tested and the selected conditions were applied to the synthesis of the natural alkaloid Norallosedamine and other derivatives.
An efficient approach to 2-substituted N-tosylpiperdines: asymmetric synthesis of 2-(2-hydroxy substituted)piperidine alkaloids
Bisai, Alakesh,Singh, Vinod K.
, p. 1907 - 1910 (2007/10/03)
We have developed an efficient and a general approach to chiral 2-substituted N-tosylpiperidines starting from chiral α-substituted-N-tosylaziridines. Using this approach, we have synthesized (+)-coniine. The synthesis of chiral N-tosyl-2-piperidinylethanol 15 and ent-15, was achieved from l- and d-aspartic acids, respectively in few steps. Piperidine 15 was converted into 2-(2-hydroxysubstituted)piperidines of type 2 in optically active form. By applying this strategy, asymmetric syntheses of halosaline (R,R)-2a, (+)- and (-)-sedamine 2b, (+)- and (-)-allosedamine 2c, (+)- and (-)-sedridine 2d, (+)- and (-)-allosedridine 2e, (+)-tetraponerine T-3 3a, T-4 3c, T-7 3b, and T-8 3d have been achieved in high yields. These stereoisomers can be interconverted via Mitsunobu inversion in excellent yields.
Diastereoselective, one-pot synthesis of γ-amino alcohols from ketimines
Veenstra,Kinderman
, p. 1109 - 1112 (2007/10/03)
Deprotonation of ketimines with lithium diisopropyl amide, followed by reaction with aldehydes and subsequent reduction with aluminium hydrides gave γ-amino alcohols with moderate to good syn selectivity. The scope and limitations of this preparative meth
A concise synthesis of homochiral sedamines and related alkaloids. A new reductive application of Jacobsen's catalyst
Yu, Chu-Yi,Meth-Cohn, Otto
, p. 6665 - 6668 (2007/10/03)
Two methods for the generation of both enantiomers of sedamine [1- methyl-2-(2-phenyl-2-hydroxy-1-ethyl)piperidine] in high optical purity have been elaborated. The first utilises the lipase-mediated kinetic resolution of racemic acetates and the second involves the NaBH4 mediated reduction of ketones catalysed by Jacobsen's catalyst. Some related applications of these reactions are also disclosed.
Trimethylsilyl trifluoromethanesulfonate (TMSOTf) catalyzed amidoalkylation of silylenolethers. Stereocontrolled syntheses of (+/-)-sedamine and (+/-)-norsedamine
Pilli,Dias
, p. 2213 - 2229 (2007/10/02)
Trimethylsilyl trifluoromethanesulfonate (TMSOTf) catalyzed addition of 1-trimethylsilyloxy-1-phenylethene to N-ethoxycarbonyl- and N-tert-butoxycarbonyl-2-ethoxypiperidines (3a and 3b, respectively) afforded the corresponding ketocarbamates 4a and 4b, in excellent yields. Stereoselective conversion to (±)-norsedamine (7) and (±)-sedamine (8) is described.
Nitrone Cycloadditions: Synthesis of (+/-)-Andrachamine
Carruthers, William,Coggins, Peter,Weston, John B.
, p. 2323 - 2327 (2007/10/02)
The usefulness of the cycloaddition of alkenes to 2-alkyl-2,3,4,5-tetrahydropyridine oxides for the preparation of trans-2,6-dialkylpiperidines is confirmed by a stereoselective synthesis of (+/-)-andrachamine.Peroxy acid oxidation of 9-oxa-1-azabicyclononanes does not lead regioselectively to the corresponding 2-alkyl-2,3,4,5-tetrahydropyridine oxide, as had previously been claimed.
