37 research outputs found
The non-occurrence of events
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Rhodium(III)-Catalyzed Regio- and Stereoselective C–H Allylation of Arenes with Vinyl Benzoxazinanones
Vinyl
benzoxazinanone was applied as an electrophilic allylating reagent
for a series of arenes under redox-neutral Rh(III) catalysis. This
reaction occurs in high efficiency under mild conditions to afford
allylarenes bearing a sulfonamide functionality in exclusively <i>E</i>-selectivity. This allylation system combines C–H
activation of arenes and scission of an unstrained six-membered ring
Rhodium(III)-Catalyzed Acylation of C(sp(3))-H Bonds with Cyclopropenones
Rh(III)-catalyzed activation and acylation of sp(3) C-H bonds has been realized with diarylcyclopropenone as an acylating reagent. Both benzylic C-H in 8-methylquinolines and unactivated C-H in 2-alkylpyridines are applicable in this C-H acylation reaction, providing enones in good yields under redox-neutral conditions
Rhodium(III)-catalyzed synthesis of indanones via C-H activation of phenacyl phosphoniums and coupling with olefins
Phosphonium ylide acts as an efficient bifunctional directing group in Rh(III)-catalyzed C-H activation of arenes and oxidative coupling with activated olefins, leading to facile construction of indanones via a sequence of oxidative olefination and carboannulation. The phosphonium moiety functions as an oxophilic group, and dephosphination triggers a nucleophilic cyclization
Manganese(I)-Catalyzed Synthesis of Fused Eight- and Four-Membered Carbocycles via C-H Activation and Pericyclic Reactions
Pericyclic reactions have allowed facile construction of complex cycles. On the other hand, metal-catalyzed C-H activation has been established as an important strategy for rapid synthesis of complex structures. The two areas are integrated in Mn(I)-catalyzed redox-neutral coupling of 3-alkenyl- and 3-allylindoles with propargylic carbonates, which occurred via C-H allenylation with subsequent pericyclic reactions to afford fused eight- and four-membered carbocycles, respectively
Twofold C-H Activation-Based Enantio- and Diastereoselective C-H Arylation Using Diarylacetylenes as Rare Arylating Reagents
C-H bond activation has been established as an attractive strategy to
access axially chiral biaryls, and the most straightforward method is direct
C-H arylation of arenes. However, the arylating source has been limited to
several classes of reactive and bulky reagents. Reported herein is
rhodium-catalyzed 1:2 coupling of diarylphosphinic amides and diarylacetylenes
for enantio- and diastereoselective construction of biaryls with both central
and axial chirality. This twofold C-H activation reaction stays contrast to the
previously explored Miura-Satoh type 1:2 coupling of arenes and alkynes in
terms of chemoselectivity and proceeded under mild conditions with the alkyne
acting as a rare arylating reagent. Both C-H activation events are
stereo-determining and are under catalyst control, with the 2nd C-H
activation being diastereo-determining in a remote fashion. Analysis of the
stereochemistries of the major and side products suggests moderated
enantioselectivity of the initial C-H activation-desymmetrization process.
However, the minor stereoisomeric (R) intermediate is consumed more
readily in undesired protonolysis, eventually resulting in high enantio- and
diastereoselectivity of the major product.</p
Rhodium-Catalyzed Amination and Annulation of Arenes with Anthranils: C-H Activation Assisted by Weakly Coordinating Amides
A rhodium(III)-catalyzed C-H amination of benzamides and isoquinolones with anthranils has been realized under assistance of weakly coordinating amide, leading to a bifunctionalized amination product which can further cyclize to acridine under insitu or ex situ conditions
Cobalt(III)-catalyzed efficient synthesis of indenones through carboannulation of benzoates and alkynes
Cobalt(III)-catalyzed C-H activation of simple benzoate esters has been achieved, and redox-neutral annulative coupling with internal alkynes allowed efficient synthesis of indenones. The employment of the weak and simple ester directing group makes it an attractive protocol in carbocycle synthesis
Access to Quaternary Stereogenic Centers via Rhodium(III)-Catalyzed Annulations between 2-Phenylindoles and Ketenes
Rh(III)-catalyzed C-H activation of arenes and mild oxidative [4 + 2] annulative coupling with ketenes have been realized. The uniquely high reactivity of the C(3) of 2-phenylindoles was successfully utilized to facilitate the reductive elimination process, leading to efficient synthesis of cyclic products with a quaternary carbon stereocenter
rhiiicatalyzedcouplingofnitroneswithalkynesforthesynthesisofindolines
三价铑在氧化还原中性条件下催化硝酮与炔发生偶联,经过氮芳环的碳氢键活化和氧转移可以高化学选择性、中等到良好非对映选择性的得到三取代二氢吲哚