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José L. García Ruano - One of the best experts on this subject based on the ideXlab platform.
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Stereocontrolled fluorobenzylation of vinyl sulfones and α,β-unsaturated esters mediated by a remote Sulfinyl Group. Synthesis of functionalized enantiomerically pure benzylic fluorides.
Journal of Organic Chemistry, 2012Co-Authors: José L. García Ruano, José A. Fernández-salas, M. Carmen MaestroAbstract:A Sulfinyl Group in an ortho position confers enough chemical and configurational stability to monofluorobenzylcarbanions to evolve in a completely stereoselective way in their reactions with β-substituted vinyl sulfones and α,β-unsaturated esters. Reactions afford easily separable mixtures of two epimers differing in the configuration of the center derived from the Michael acceptor (up to 98% de). They can be easily converted into enantiomerically pure γ-fluorinated γ-phenylsulfones and γ-phenylesters bearing two chiral centers.
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Asymmetric synthesis of (S)-(-)-xylopinine. Use of the Sulfinyl Group as an ipso director in aromatic SE.
Journal of Organic Chemistry, 2011Co-Authors: Virginia M. Mastranzo, Francisco Yuste, Benjamín Ortiz, Rubén Sánchez-obregón, Rubén A. Toscano, José L. García RuanoAbstract:Optically pure (S)-(−)-xylopinine 2 was prepared in three steps in 52% overall yield. Thus, condensation of the carbanion derived from (S)-4 with the (S)-(E)-Sulfinylimine 5 gave a 2:1 mixture of tetrahydroisoquinolines 6a and 6b, differing only in configuration at sulfur. N-DeSulfinylation of this mixture gave the diastereomeric sulfoxides which, without separation, were converted into (S)-(−)-xylopinine (2) with loss of the Sulfinyl moieties under Pictet–Spengler conditions. This unprecedented ipso electrophilic substitution of a Sulfinyl Group may have synthetic implications beyond that described in this work.
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Asymmetric synthesis of benzylic quaternary difunctionalized carbons mediated by a remote Sulfinyl Group.
Journal of Organic Chemistry, 2011Co-Authors: José L. García Ruano, Esther Torrente, Ana M. Martín-castroAbstract:Enantiomerically enriched α-aryl α-cyanoacetates and α-aryl α-acylacetonitriles bearing a benzylic quaternary stereocenter have been readily synthesized by stereoselective reaction of 2-alkyl-2-[2-(p-tolylSulfinyl)phenyl]acetonitriles with different acylating and alkoxycarbonylating reagents under basic conditions. The stereoselectivity of the reactions proved closely dependent on the nature of the intermediate carbanionic species, the evolution of which was effectively controlled by a Sulfinyl Group as a remote chiral auxiliary.
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Complete Stereocontrol in Organocatalytic Additions of β‐Ketosulfoxides to Conjugated Aldehydes
Chemistry: A European Journal, 2011Co-Authors: José L. García Ruano, Cuauhtemoc Alvarado, Sergio Díaz-tendero, José AlemánAbstract:The use of β-ketosulfoxides as nucleophiles in reactions with α,β-unsaturated aldehydes catalyzed by proline derivatives allows complete control of configuration at the two chiral centers that are created during 1,4-addition reactions. The Sulfinyl Group can be used to create additional chiral centers in the resulting compounds and then removed while preserving the chirality of the carbon joined to the sulfur. The catalyst and the Sulfinyl Group are mainly responsible for the configurational control of the carbon atoms acting as electrophile and nucleophile, respectively, which allows the preparation of the four possible diastereoisomers in optically pure form. Theoretical calculations of the possible chiral nucleophilic species bearing diastereotopic faces allow us to postulate, for the first time, that enolates, instead of enols, are the active reagents in these reactions.
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stereoselective synthesis of 2 3 epoxy alcohols mediated by a remote Sulfinyl Group
Tetrahedron, 2010Co-Authors: José L. García Ruano, Francisco Tato, Esther Torrente, Saverio Florio, A M Martincastro, Giovanna M Tocco, Vito CapriatiAbstract:The influence of the Sulfinyl Group as a chiral auxiliary in the stereoselective addition of oxiranyllithiums to (S)-2-p-tolylSulfinylbenzaldehyde has been studied. All reactions evolve with retention of configuration at the starting lithiated carbon. Completely stereoselective additions have been observed when configurations at sulfur and the lithiated carbon are different (matched pair), whereas variable dr's values (ranging between 52:48 and >99:<1%) when they are identical (mismatched pair).
Sadagopan Raghavan - One of the best experts on this subject based on the ideXlab platform.
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total synthesis of 2 s 3 r zoapatanol exploiting the b alkyl suzuki reaction and the nucleophilic potential of the Sulfinyl Group
Chemistry: A European Journal, 2011Co-Authors: Sadagopan Raghavan, Vaddela Sudheer BabuAbstract:A stereoselective synthesis of the diterpenoid oxepane (+)-zoapatanol is described. The key steps include a B-alkyl Suzuki cross-coupling reaction for the stereoselective synthesis of trisubstituted alkenes, creation of the two stereogenic centers on the oxepane ring by heterofunctionalization of an alkene through substrate control exploiting the nucleophilic potential of an intramolecular Sulfinyl Group, and transformation of a β-hydroxy sulfoxide into a terminal alkene.
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Total Synthesis of (+)‐(2′S,3′R)‐Zoapatanol Exploiting the B‐Alkyl Suzuki Reaction and the Nucleophilic Potential of the Sulfinyl Group
Chemistry: A European Journal, 2011Co-Authors: Sadagopan Raghavan, Vaddela Sudheer BabuAbstract:A stereoselective synthesis of the diterpenoid oxepane (+)-zoapatanol is described. The key steps include a B-alkyl Suzuki cross-coupling reaction for the stereoselective synthesis of trisubstituted alkenes, creation of the two stereogenic centers on the oxepane ring by heterofunctionalization of an alkene through substrate control exploiting the nucleophilic potential of an intramolecular Sulfinyl Group, and transformation of a β-hydroxy sulfoxide into a terminal alkene.
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Mercury(II)-mediated cleavage of cyclopropylcarbinols by an intramolecular Sulfinyl Group as a stereo- and regioselective route to stereotriads and stereotetrads.
Journal of Organic Chemistry, 2010Co-Authors: Sadagopan Raghavan, Vaddela Sudheer Babu, B. SridharAbstract:Mercury(II) salt mediated opening of cyclopropylcarbinols by an intramolecular Sulfinyl Group is disclosed. All four diastereomeric stereotriads have been prepared from cis- and trans-disubstituted cyclopropanes. The trisubstituted cyclopropanes also react regio- and stereoselectively to afford products possessing quaternary stereogenic centers. The reaction is clean and general.
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A short stereoselective synthesis of (+)-boronolide
Tetrahedron Letters, 2006Co-Authors: Sadagopan Raghavan, V. KrishnaiahAbstract:Abstract A short and stereoselective synthesis of (+)-boronolide via oxidative functionalization of an olefin using a pendant Sulfinyl Group is described. Diastereoselective allylation was performed using Keck’s protocol and the lactone moiety was prepared by ring closing metathesis.
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Stereoselective synthesis of (−)-allosedamine and (1R,3R)-HPA-12 from β-p-toluenesulfonamido-γ,δ-unsaturated sulfoxide☆
Tetrahedron, 2004Co-Authors: Sadagopan Raghavan, A. RajenderAbstract:Abstract A stereoselective synthesis of (−)-allosedamine and HPA-12 is disclosed. The key steps of the synthesis include the diastereoselective synthesis of a β-sulfonamido unsaturated sulfoxide, elaboration of a bromohydrin via intramolecular Sulfinyl Group participation and a ring-closing metathesis reaction for the construction of the piperidine ring of allosedamine.
Takeshi Imanishi - One of the best experts on this subject based on the ideXlab platform.
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Asymmetric induction by Sulfinyl chirality: a total synthesis of (+)-talaromycin A and (−)-talaromycin B
Tetrahedron Letters, 2001Co-Authors: Chuzo Iwata, Masahiro Fujita, Yasunori Moritani, Kohji Hattori, Takeshi ImanishiAbstract:Abstract A total synthesis of (+)-talaromycin A and (−)-talaromycin B was accomplished by means of successive asymmetric induction of all chiral centers using a chiral Sulfinyl Group.
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Studies on novel and chiral 1,4-dihydropyridines. V. Hantzsch-type 1,4-dihydropyridines having a chiral Sulfinyl Group: Syntheses, structures, and biological activity as a calcium channel antagonist
Tetrahedron, 1997Co-Authors: Kazuyuki Miyashita, M. Nishimoto, Hidenobu Murafuji, Satoshi Obika, Tetsuya Ishino, Osamu Muraoka, Takeshi ImanishiAbstract:Abstract 4-Aryl and 4-methyl substituted Hantzsch-type 1,4-dihydropyridines having a chiral Sulfinyl Group as an electron-withdrawing Group were successfully synthesized in an optically active form from β-ketosulfoxides via two routes. The relationship between calcium channel antagonist activity and the structures of 4-aryl derivatives was also studied.
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novel and regioselective lithiation of the unsymmetrical hantzsch type 1 4 dihydropyridine by participation of the neighboring Sulfinyl Group
Chemical & Pharmaceutical Bulletin, 1996Co-Authors: Kazuyuki Miyashita, M. Nishimoto, Hidenobu Murafuji, Satoshi Obika, Takeshi ImanishiAbstract:The C-6 methyl Group of methyl (4R, SS)-2, 4, 6-trimethyl-5-(p-tolylSulfinyl)-1, 4-dihydropyridine-3-carboxylate (2) was found to be regioselectively lithiated by participation of the neighboring Sulfinyl Group, giving rise to the 6-modified Hantzsch-type compounds by treatment with n-butyllihium and the electrophiles.
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Effect of the neighbouring oxygenated substituent on asymmetric reduction with Hantzsch-type 1,4-dihydropyridines having a chiral Sulfinyl Group
Chemical Communications, 1996Co-Authors: Kazuyuki Miyashita, M. Nishimoto, Hidenobu Murafuji, Asuka Murakami, Satoshi Obika, Toshimasa Ishida, Takeshi ImanishiAbstract:Introduction of the oxygen substitutent at C-6 of the Hantzsch-type compound having a Sulfinyl Group at C-5 affects the reduction of ketones with respect to both reactivity and stereoselectivity.
Vaddela Sudheer Babu - One of the best experts on this subject based on the ideXlab platform.
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total synthesis of 2 s 3 r zoapatanol exploiting the b alkyl suzuki reaction and the nucleophilic potential of the Sulfinyl Group
Chemistry: A European Journal, 2011Co-Authors: Sadagopan Raghavan, Vaddela Sudheer BabuAbstract:A stereoselective synthesis of the diterpenoid oxepane (+)-zoapatanol is described. The key steps include a B-alkyl Suzuki cross-coupling reaction for the stereoselective synthesis of trisubstituted alkenes, creation of the two stereogenic centers on the oxepane ring by heterofunctionalization of an alkene through substrate control exploiting the nucleophilic potential of an intramolecular Sulfinyl Group, and transformation of a β-hydroxy sulfoxide into a terminal alkene.
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Total Synthesis of (+)‐(2′S,3′R)‐Zoapatanol Exploiting the B‐Alkyl Suzuki Reaction and the Nucleophilic Potential of the Sulfinyl Group
Chemistry: A European Journal, 2011Co-Authors: Sadagopan Raghavan, Vaddela Sudheer BabuAbstract:A stereoselective synthesis of the diterpenoid oxepane (+)-zoapatanol is described. The key steps include a B-alkyl Suzuki cross-coupling reaction for the stereoselective synthesis of trisubstituted alkenes, creation of the two stereogenic centers on the oxepane ring by heterofunctionalization of an alkene through substrate control exploiting the nucleophilic potential of an intramolecular Sulfinyl Group, and transformation of a β-hydroxy sulfoxide into a terminal alkene.
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Mercury(II)-mediated cleavage of cyclopropylcarbinols by an intramolecular Sulfinyl Group as a stereo- and regioselective route to stereotriads and stereotetrads.
Journal of Organic Chemistry, 2010Co-Authors: Sadagopan Raghavan, Vaddela Sudheer Babu, B. SridharAbstract:Mercury(II) salt mediated opening of cyclopropylcarbinols by an intramolecular Sulfinyl Group is disclosed. All four diastereomeric stereotriads have been prepared from cis- and trans-disubstituted cyclopropanes. The trisubstituted cyclopropanes also react regio- and stereoselectively to afford products possessing quaternary stereogenic centers. The reaction is clean and general.
Zhiwei Miao - One of the best experts on this subject based on the ideXlab platform.
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K3PO4-promoted domino reactions: diastereoselective synthesis of trans-2,3-dihydrobenzofurans from salicyl N-tert-butaneSulfinyl imines and sulfur ylides
RSC Advances, 2019Co-Authors: Minxuan Zhang, Yun Zhao, Guixian Xie, Zhiwei MiaoAbstract:An efficient domino annulation between sulfur ylides and salicyl N-tert-butylSulfinyl imines was developed. The reaction proceeds with a diastereodivergent process, the configuration of the Sulfinyl Group determining the stereochemical course of the reaction. The method allows the synthesis of a highly substituted trans-2,3-dihydrobenzofuran skeleton with high yield and good chemo- and diastereoselectivity.
