Results 141 to 150 of about 52,647 (305)

Structural revision of stemoburkilline from an E-Alkene to a Z-Alkene

, 2009
Semisynthesis studies starting from (11Z)-I',2'-didehydrostemofoline indicated that the known Stemona alkaloid stemoburkilline is the Z-isomer and not the E-isomer as initially reported.
Wilford Lie (19581559), Natasha Popcevski (19573150), Alison Ung (20118957), Araya Jatisatienr (2235439), Pitchaya Mungkornawawakul (20244840), Stephen Pyne (19586047)   +5 more
core   +1 more source

Hole‐Activated Lattice Oxygen Enables Pt‐Free Propane Dehydrogenation by Eliminating the Hydrogen Recombination Bottleneck

Angewandte Chemie, EarlyView.
Trace Mg doping into gallia–alumina generates hole‐type oxygen species that accelerate hydrogen recombination, eliminating the need for Pt promotion. The fully oxide‐based catalyst resists sintering under repeated regeneration, outperforming benchmark PtSn and CrOx catalysts with exceptional stability over 30 dehydrogenation–regeneration cycles ...
DongHwan Oh, Jaewoo Jeong, Susung Lee, Younghwan Park, Seunghyuck Chi, Yaejun Baik, Hyungjun Kim, Hyeyoung Shin, Minkee Choi   +8 more
wiley   +1 more source

Modular and Stereoselective Synthesis of Cyclobutane β‐Amino Alcohols

Angewandte Chemie, EarlyView.
Late‐stage functionalization and photoisomerization of 1,2‐azaborine leads to a general strategy for the synthesis of diversely substituted cyclobutane β‐amino alcohols. The relative stereochemistry of the resulting products is unambiguously defined by the stereospecific and stereoselective nature of the photoisomerization‐hydrogenation‐oxidation ...
Xinyu Yang, Tomoya Ozaki, Bo Li, Shih‐Yuan Liu   +3 more
wiley   +1 more source

1‐Azabicyclo[1.1.0]butanes (ABBs) on the Map: Mechanistic Pathways for Catalytic Ring Opening and Functionalizations

Angewandte Chemie, EarlyView.
Catalytic strain‐release ring opening and functionalizations of 1‐azabicyclo[1.1.0]butanes (ABBs) represent a promising strategy for accessing diverse azetidine products. These transformations proceed via polar pathways, radical pathways, and hybrid mechanisms that combine both.
James Shao‐Jiun Yang, Hsuan‐Hung Liao   +1 more
wiley   +1 more source

Janus Reactivity of a Mononuclear Non‐Heme Iron(III)‐Peroxo Complex Toward Indole Oxidation

Angewandte Chemie, EarlyView.
The iron(III)‐peroxo complex [FeIII(O2)(12‐TMC)]+ exhibits bifurcating pathways in indole oxidation. N─H indoles undergo N─H H‐atom abstraction, supported by a KIE of 5.2 for N─H/N–D 2,3‐dimethylindoles, whereas N‐methylindoles react via electrophilic addition of the iron‐peroxo group to the C2–C3 double bond of the indole ring, forming iron ...
Wenjuan Zhu, Peng Wu, Binju Wang, Kallol Ray, Wonwoo Nam   +4 more
wiley   +1 more source

Second‐Sphere Aromatic Substitutions That Tune H‐Atom Transfer Reactivity Observed for a Series of S = 1 Nonheme FeIV=O Complexes: An Enthalpy‐Entropy Compensation Effect

Angewandte Chemie, EarlyView.
A series of oxoiron(IV) complexes was synthesized to determine the impact of electronically tuned aromatic substitution in the secondary sphere of the ligand. Despite possessing identical electronic properties, they show significant differences in C─H oxidation reactions.
Abhishek Das, Jin Xiong, Victor G. Young Jr., Yisong Guo, Marcel Swart, Lawrence Que Jr.   +5 more
wiley   +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   +1 more source

Structure and Biosynthesis of Mangotoxin Produced by the Plant Pathogen Pseudomonas syringae

Angewandte Chemie, EarlyView.
The structure of mangotoxin remained elusive for over two decades. Here, mangotoxin was isolated from the native producer, Pseudomonas syringae pv. syringae, and was determined to be an alkyne‐containing dipeptide. Mangotoxin inhibited the growth of multidrug‐resistant human pathogen Klebsiella pneumoniae.
Alexis H. Murray, Sohan Hazra, Ryan W. Mull, Erinn M. O'Neill, Bo Li   +4 more
wiley   +1 more source

Redox‐Neutral Vicinal Dialkylation of Aryl Boronic Esters via the Palladium/Norbornene Cooperative Catalysis

Angewandte Chemie, EarlyView.
A new mode of the palladium/norbornene (Pd/NBE) cooperative catalysis, that is, redox‐neutral difunctionalization of aryl boronic esters with two electrophiles, has been developed, which can be used to streamline the preparation of a functionalized benzoazepane.
Rong Ye, Peimiao He, Liyan Kan, Thomas R. Plambeck, Guangbin Dong   +4 more
wiley   +1 more source

Heavy‐Atom Tunneling at Room Temperature Revealed by Instanton Theory

Angewandte Chemie, EarlyView.
Usually, tunneling does not play a significant role in chemical reactions except at low temperature, especially when heavy atoms are involved. However, using nonadiabatic instanton theory we find that heavy‐atom tunneling dominates the reaction mechanism for spin‐forbidden processes in the synthesis of strained organic molecules even at room ...
Debaarjun Mukherjee, Kamil D. Petryczkiewicz, Jeremy O. Richardson   +2 more
wiley   +1 more source