Nickel-Catalyzed Formation of 1,3-Dienes via a Highly Selective Cross-Tetramerization of Tetrafluoroethylene, Styrenes, Alkynes, and Ethylene
JacsNickel-Catalyzed Formation of 1,3-Dienes via a Highly Selective Cross-Tetramerization of Tetrafluoroethylene, Styrenes, Alkynes, and Ethylene: In the presence of a catalytic amount of Ni(cod)2 (cod = 1,5-cyclooctadiene) and PCy3 (Cy = cyclohexyl), the cross-tetramerization of tetrafluoroethylene (TFE), alkynes, and ethylene occurred in a highly selective manner to afford a variety of 1,3-dienes with a 3,3,4,4-tetrafluorobutyl chain. (Source: Organometallic Current)
Source: Organometallic Current - November 29, 2017 Category: Chemistry Tags: Ni Catalyzed Source Type: blogs
Copper-Catalyzed Alkylation of Aliphatic Amines Induced by Visible Light
We report herein that primary aliphatic amines can be cleanly mono-alkylated by unact ivated secondary alkyl iodides in the presence of visible light and a copper catalyst. (Source: Organometallic Current)
Source: Organometallic Current - November 29, 2017 Category: Chemistry Tags: Alkylation Cu catalyzed Visible light Source Type: blogs
Radical Multicomponent Carboamination of [1.1.1]Propellane
JacsRadical Multicomponent Carboamination of [1.1.1]Propellane: Three-dimensional, small-ring scaffolds are very important in modern drug discovery to expand the available drug-like chemical space and to optimize drug candidates. Among them, bicyclo[1.1.1]pentane (BCP) is regarded as a high-value bioisostere for a phenyl ring ortert-butyl group; it provides an option to generate drug-like molecules with good passive permeability, high aqueous solubility, and improved metabolic stability, though the lack of methodology to functionalize BCP remains a significant challenge. (Source: Organometallic Current)
Source: Organometallic Current - November 29, 2017 Category: Chemistry Tags: Carboamination Fe catalyzed Radical Reactions Source Type: blogs
Enantiospecific sp2 –sp3 Coupling of ortho‐ and para‐Phenols with Secondary and Tertiary Boronic Esters
AngewchemEnantiospecific sp2 –sp3 Coupling of ortho‐ and para‐Phenols with Secondary and Tertiary Boronic Esters: The coupling of ortho ‐ and para‐phenols with secondary and tertiary boronic esters has been explored. In the case of para‐substituted phenols, after reaction of a dilithio phenolate species with a boronic... (Source: Organometallic Current)
Source: Organometallic Current - November 29, 2017 Category: Chemistry Tags: Enantioselective Synthetic method Source Type: blogs
Cobalt ‐Catalyzed Suzuki Biaryl Coupling of Aryl Halides
AngewchemCobalt ‐Catalyzed Suzuki Biaryl Coupling of Aryl Halides: Readily accessed cobalt pre ‐catalysts with N‐heterocyclic carbene ligands catalyze the Suzuki cross‐coupling of aryl chlorides and bromides with alkyllithium‐activated arylboronic pinacolate esters. Preliminary... (Source: Organometallic Current)
Source: Organometallic Current - November 29, 2017 Category: Chemistry Tags: Arylation C-C Bond Forming Co catalyzed Source Type: blogs
Catalytic Enantioselective Hetero-dimerization of Acrylates and 1,3-Dienes
JacsCatalytic Enantioselective Hetero-dimerization of Acrylates and 1,3-Dienes: 1,3-Dienes are ubiquitous and easily synthesized starting materials for organic synthesis, and alkyl acrylates are among the most abundant and cheapest feedstock carbon sources. A practical, highly enantioselective union of these two readily available precursors giving valuable, enantio-pure skipped 1,4-diene esters (with two configurationally defined double bonds) is reported. The process uses commercially available cobalt salts and chiral ligands. (Source: Organometallic Current)
Source: Organometallic Current - November 28, 2017 Category: Chemistry Tags: Co catalyzed Dimerization Source Type: blogs
Total Syntheses of ( −)-Majucin and (−)-Jiadifenoxolane A, Complex Majucin-Type Illicium Sesquiterpenes
We report the first chemical syntheses of both ( −)-majucin and (−)-jiadifenoxolane A via 10 net oxidations from the ubiquitous terpene (+)-cedrol. Additionally, this approach allows for access to other majucin-type sesquiterpenes, like (−)-jiadifenolide, (−)-jiadifenin, and (−)-(1R,10S)-2-oxo-3,4-dehydroxyneomajucin (ODNM) along the synthetic pathway. Site-selective aliphatic C(sp3)-H bond oxidation reactions serve as the cornerstone of this work which offers access to highly oxidized natural products from an abundant and renewable terpene feedstock. (Source: Organometallic Current)
Source: Organometallic Current - November 28, 2017 Category: Chemistry Tags: Total synthesis Source Type: blogs
Electrochemical Cobalt-Catalyzed C –H Oxygenation at Room Temperature
JacsElectrochemical Cobalt-Catalyzed C –H Oxygenation at Room Temperature: Electrochemical cobalt-catalyzed C –H functionalizations were achieved in terms of C–H oxygenation under mild conditions at 23 °C. The robust electrochemical C–H functionalization was characterized by ample substrate scope, whereas mechanistic studies provided support for a facile C–H cleavage. The electrochemical cobalt -catalyzed C–H oxygenation proved viable on arenes and alkenes with excellent levels of positional and diastereo-selectivity, avoiding the use of stoichiometric silver(I) oxidants under ambient conditions. (Source: Organometallic Current)
Source: Organometallic Current - November 28, 2017 Category: Chemistry Tags: C-H Oxygenation Co catalyzed Electrochemical Room Temp Rxn Source Type: blogs
Total Synthesis of ( −)-Himalensine A
JacsTotal Synthesis of ( −)-Himalensine A: The first enantioselective synthesis of ( −)-himalensine A has been achieved in 22 steps. The synthesis was enabled by a novel catalytic, enantioselective prototropic shift/furan Diels–Alder (IMDAF) cascade to construct the ACD tricyclic core. A reductive radical cyclization cascade was utilized to build the B ring, and end-game man ipulations featuring a molecular oxygen mediated γ-CH oxidation, a Stetter cyclization to access the pendant cyclopentenone, and a highly chemoselective lactam reduction delivered the natural product target. (Source: Organometallic Current)
Source: Organometallic Current - November 28, 2017 Category: Chemistry Tags: Total synthesis Source Type: blogs
One ‐Pot Synthesis of Cyclopropane‐Fused Cyclic Amidines: An Oxidative Carbanion Cyclization
AngewchemOne ‐Pot Synthesis of Cyclopropane‐Fused Cyclic Amidines: An Oxidative Carbanion Cyclization: A novel and efficient one ‐pot method has been developed for the synthesis of cyclopropane‐fused bicyclic amidines on the basis of a CuBr2‐mediated oxidative cyclization of carbanions. The usefulness of... (Source: Organometallic Current)
Source: Organometallic Current - November 28, 2017 Category: Chemistry Tags: Cu catalyzed Cyclopropanation Source Type: blogs
Ligand ‐controlled Regiodivergent C−H Alkenylation of Pyrazoles and its Application to the Synthesis of Indazoles
AngewchemLigand ‐controlled Regiodivergent C−H Alkenylation of Pyrazoles and its Application to the Synthesis of Indazoles: Regioselective C4 ‐, C5‐, and di‐alkenylations of pyrazoles were achieved. An electrophilic Pd catalyst generated by trifluoroacetic acid (TFA) and 4,5‐diazafluoren‐9‐one (DAF) leads to C4‐alkenylation,... (Source: Organometallic Current)
Source: Organometallic Current - November 28, 2017 Category: Chemistry Tags: C-H Alkenylation Pd Catalyzed Source Type: blogs
Synthesis of a Phlorin from a Meso ‐Fused Anthriporphyrin by a Diels–Alder Strategy
AngewchemSynthesis of a Phlorin from a Meso ‐Fused Anthriporphyrin by a Diels–Alder Strategy: An anthracene ‐containing meso‐fused carbaporphyrin, which has extended π‐conjugation pathways as compared to the corresponding naphthalene‐containing carbaporphyrin, has been synthesized. The weak global... (Source: Organometallic Current)
Source: Organometallic Current - November 28, 2017 Category: Chemistry Tags: Phorphyrins Source Type: blogs
Nucleophilic Arylation of N,O ‐Ketene Acetals with Triaryl Aluminum Reagents: Access to α‐Aryl Amides through an Umpolung Process
AngewchemNucleophilic Arylation of N,O ‐Ketene Acetals with Triaryl Aluminum Reagents: Access to α‐Aryl Amides through an Umpolung Process: A novel approach for the umpolung α‐arylation of amides is presented. By the nucleophilic phenylation of O‐silyl N,O‐ketene acetals, generated in situ from N‐alkoxy amides, a phenyl group can be introduced... (Source: Organometallic Current)
Source: Organometallic Current - November 28, 2017 Category: Chemistry Tags: Umpolung Source Type: blogs
Enantioselective and Collective Total Syntheses of Xanthanolides
AngewchemEnantioselective and Collective Total Syntheses of Xanthanolides: An enantioselective synthesis of (+) ‐8‐epi‐xanthatin hinging on a chiral phosphoric acid catalyzed tandem allylboration/lactonization reaction is reported. With (+)‐8‐epi‐xanthatin as the precursor, the... (Source: Organometallic Current)
Source: Organometallic Current - November 28, 2017 Category: Chemistry Tags: Enantioselective Natural products Total synthesis Source Type: blogs
Enantioselective Rhodium ‐Catalyzed Coupling of Arylboronic Acids, 1,3‐Enynes, and Imines by Alkenyl‐to‐Allyl 1,4‐Rhodium(I) Migration
AngewchemEnantioselective Rhodium ‐Catalyzed Coupling of Arylboronic Acids, 1,3‐Enynes, and Imines by Alkenyl‐to‐Allyl 1,4‐Rhodium(I) Migration: A chiral rhodium complex catalyzes the highly enantioselective coupling of arylboronic acids, 1,3 ‐enynes, and imines to give homoallylic sulfamates. The key step is the generation of allylrhodium(I) species... (Source: Organometallic Current)
Source: Organometallic Current - November 28, 2017 Category: Chemistry Tags: Enantioselective Rh Catalyzed Source Type: blogs
