Results 61 to 70 of about 30,863 (282)

Do Reaction Conditions Affect the Stereoselectivity in the Staudinger Reaction?

, 2016
The stereochemistry is one of the critical issues in the Staudinger reaction. We have proposed the origin of the stereoselectivity recently. The effects of solvents, additives, and pathways of ketene generation on the stereoselectivity were investigated ...
Yikai Wang (1706548), Lei Jiao (780172), Da-Ming Du (1478770), Jiaxi Xu (681245), Yong Liang (131898)   +4 more
core   +1 more source

Noncanonical Peloruside A Biosynthesis by an Uncultivated Verrucomicrobiota Symbiont

Angewandte Chemie, EarlyView.
Noncanonical biochemistry of the peloruside PKS characterized in this work, comprising double bond generation by a noncanonical tridomain (blue), acetyl‐CoA recycling (orange), and proofreading systems (purple and yellow). The Z‐double bond is installed by TEB1 through O‐acetylation and acetate elimination. The acyl ligase PelB (AL, orange) selectively
Amy E. Fraley, Michael Rust, Moritz Wagner, Ida R. Hipfinger, Paul J. N. Böhm, Cora L. Dieterich, Christopher M. Field, Michael J. Page, Jeremy G. Owen, Robert A. Keyzers, Shinichi Sunagawa, Jörn Piel   +11 more
wiley   +2 more sources

A stereoselective synthesis of (+)-boronolide [PDF]

Tetrahedron Letters, 2000
A stereoselective synthesis of (+)-boronolide is described. The key steps involve a stereoselective reduction of an α-hydroxy ketone, allylation of an α-hydroxy aldehyde and a ring-closing olefin metathesis of a homoallylic alcohol derived acrylate ester utilizing Grubbs' catalyst.
Arun K, Ghosh, Geoffrey, Bilcer
openaire   +2 more sources

Electrochemically Driven Regioselective Radical Functionalization of Allenes: Scope and Mechanistic Insights

Advanced Science, EarlyView.
Allenes emerge as powerful platforms for electrochemical functionalization through radical pathways. Selective radical addition at the central carbon triggers anodic oxidation and intramolecular cyclization, enabling efficient synthesis of oxazolines and oxazolidine‐2‐imines without external oxidants.
Pranjal Pyne, Prateek Saini, Rohel Hoque, Shivam Pandey, Srinivasan Ramakrishnan, Chandra M. R. Volla   +5 more
wiley   +1 more source

Recent Advances in the Stereoselective Total Synthesis of Natural Pyranones Having Long Side Chains

Molecules, 2020
Pyranone natural products have attracted great attention in recent years from chemists and biologists due to their fascinating stereoisomeric structural features and impressive bioactivities.
Satya Kumar Avula, Biswanath Das, Rene Csuk, Ahmed Al-Rawahi, Ahmed Al-Harrasi   +4 more
doaj   +1 more source

Cobalt‐Catalyzed Asymmetric Construction of Boron Stereocenters With C–N Axial Chirality

Advanced Science, EarlyView.
A cobalt/Salox‐catalyzed one‐pot annulation enables enantioselective formation of B‐stereogenic centers and C─N axial chirality via C─H/N─H annulation, affording diverse fluorescent products with high stereocontrol and optoelectronic potential. ABSTRACT The efficient construction of boron stereogenic centers alongside axial chirality remains a ...
Subramani Kumaran, Harihara Subramanian Ravi Sankar, Pritam Maity, J. Richard Premkumar, Abir Das, Basker Sundararaju   +5 more
wiley   +1 more source

Highly Enantio‐ and Diastereoselective Synthesis of Tetrahydrofuran Frameworks via Chiral Lewis Acid‐Catalyzed Formal [3+2] Cycloaddition of Allylsilanes

Angewandte Chemie, EarlyView.
The first catalytic asymmetric formal [3+2] cycloaddition of allylsilanes delivers cis‐2,5‐disubstituted tetrahydrofuran‐3‐ones that serve as versatile intermediates for the synthesis of diverse bioactive scaffolds. ABSTRACT A formal [3+2] cycloaddition via cyclization/1,2‐hydride shift initiated by nucleophilic attack of allylsilanes has been ...
Hosung Lee, Dong Kyu Kim, Pingshan Xin, Jin Won Lee, Terim Seo, Do Hyun Ryu   +5 more
wiley   +2 more sources

NiH‐Catalyzed Enantio‐ and Regioselective Hydroselenylation of Unactivated Alkenes

Advanced Science, EarlyView.
Nickel‐hydride‐catalyzed enantio‐ and regioselective hydroselenylation of unactivated alkenes provides access to chiral organoselenium compounds. Enantiodetermining Ni–H insertion followed by single‐electron diselenide activation generates selenyl radical.
Hyung‐Joon Kang, Jaehun Kim, Sungwoo Hong   +2 more
wiley   +1 more source

Direct Access to Chiral Piperidines by Enantioselective HAT‐Initiated C(sp3)─H Oxidation

Angewandte Chemie, EarlyView.
The direct desymmetrization of piperidines is achieved through manganese‐catalyzed enantioselective α‐C(sp3)─H oxidation with hydrogen peroxide, affording versatile chiral N,O‐acetals in good yields and with high enantio‐ and diastereoselectivity. These intermediates provide access to diverse functionalized piperidines with retention of chirality ...
Sethuraman Muthuramalingam, Josep M. Luis, Arnau Call, Quentin Lefebvre, Matthew S. Sigman, Miquel Costas   +5 more
wiley   +2 more sources

Enantioselective Access to Trifluoromethylated Spirocyclopropyl Heterocycles

Advanced Science, EarlyView.
We report a rhodium‐catalyzed asymmetric [2+1] spirocyclopropanation of methylene azacycles with trifluoromethyl carbenes in situ derived from fluoroalkyl triftosylhydrazones. ABSTRACT Chiral spirocyclopropyl heterocycles have emerged as privileged three‐dimensional structural motifs in medicinal chemistry.
Yuanhao Zhu, Youzhi Xu, Weitao Zhang, Yongyue Ning, Yaojia Jiang, Yongquan Ning, Genping Huang, Jiawei Cheng, Paramasivam Sivaguru, Xihe Bi   +9 more
wiley   +1 more source