Palladium-Catalyzed Intermolecular Dehydrogenative Aminohalogenation of Alkenes under Molecular Oxygen: An Approach to Brominated Enamines

Ji, Xiaochen; Huang, Huawen; Wu, Wanqing; Jiang, Huanfeng

doi:10.1021/ja401034g

Cited by 103 publications

(48 citation statements)

References 70 publications

(16 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When both palladium and copper were absent, no product was detected. Also noteworthy is that Jiang and co‐workers did not observe such bromination under their conditions 1a…”

Section: Methodsmentioning

confidence: 89%

“…Changing the solvent from toluene to acetonitrile, dioxane, DCE, and DMF affected the catalysis negatively (Table 1, entries 15–18). In THF, the solvent of choice in Jiang’s study,1a unbrominated Z ‐enamide 4 a was formed in 82 % yield (Table 1, entry 19) 5. 12 Attempts to reduce the amount of LiBr showed that the yield of 3 a remained the same (78 %) when 3 equiv (instead of the originally used 4 equiv) of the salt were applied (Table 1, entry 20 versus entry 3).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Palladium/Copper‐Cocatalyzed Oxidative Amidobrominations of Alkenes

Chen

Bohmann

Wang

et al. 2015

Chemistry A European J

View full text Add to dashboard Cite

In the presence of LiBr, a palladium/copper combination catalyzes dehydrogenative amidobrominations of acrylates with NH-sulfoximines, leading to N-vinylated products by dual NH/CH coupling, followed by oxidative enamide bromination. Mechanistically, the domino process is proposed to involve palladium(II) species as key intermediates. First synthetic applications of the products have been demonstrated.

show abstract

“…When both palladium and copper were absent, no product was detected. Also noteworthy is that Jiang and co‐workers did not observe such bromination under their conditions 1a…”

Section: Methodsmentioning

confidence: 89%

Section: Methodsmentioning

confidence: 99%

Palladium/Copper‐Cocatalyzed Oxidative Amidobrominations of Alkenes

Chen

Bohmann

Wang

et al. 2015

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…386 Jiang also reported an oxidiative amino bromination of electron-deficient alkenes using anilines and LiBr in 2013 (Scheme 222). 387 The authors conducted several control experiments in order to gain mechanistic insight for this transformation. They determined that a radical mechanism is most likely not operative, as TEMPO had no deleterious effects on the reaction.…”

Section: Carbohalogenation Of Alkynes By Halometalationmentioning

confidence: 99%

Modern Transition-Metal-Catalyzed Carbon–Halogen Bond Formation

2016

View full text Add to dashboard Cite

The high utility of halogenated organic compounds has prompted the development of a vast number of transformations which install the carbon-halogen motif. Traditional routes to these building blocks have commonly involved multiple steps, harsh reaction conditions, and the use of stoichiometric and/or toxic reagents. In this regard, using transition metals to catalyze the synthesis of organohalides has become a mature field in itself, and applying these technologies has allowed for a decrease in the production of waste, higher levels of regio- and stereoselectivity, and the ability to produce enantioenriched target compounds. Furthermore, transition metals offer the distinct advantage of possessing a diverse spectrum of mechanistic possibilities which translate to the capability to apply new substrate classes and afford novel and difficult-to-access structures. This Review provides comprehensive coverage of modern transition metal-catalyzed syntheses of organohalides via a diverse array of mechanisms. Attention is given to the seminal stoichiometric organometallic studies which led to the corresponding catalytic processes being realized. By breaking this field down into the synthesis of aryl, vinyl, and alkyl halides, it becomes clear which methods have surfaced as most favored for each individual class. In general, a pronounced shift toward the use of C-H bonds as key functional groups, in addition to methods which proceed by catalytic, radical-based mechanisms has occurred. Although always evolving, this field appears to be heading in the direction of using starting materials with a significantly lower degree of prefunctionalization in addition to less expensive and abundant metal catalysts.

show abstract

“…1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 data with those of known compounds. 11,31 The bromination of enamides using the same procedure ended in failure.…”

Section: Scheme 1 Chlorination Of Enaminesmentioning

confidence: 99%

“…11,31,37 The first method is limited to the production of furan skeletons, the next two produces a mixture of the two isomers and the palladium-catalyzed coupling reaction produces primary amine-substituted or sulfoximine-substituted olefins. This method is stereoselective, convenient and complementary to the known methods.…”

Section: Scheme 2 Chlorination Of Enamidesmentioning

confidence: 99%

Stereoselective Chlorination and Bromination of Enamides and Enamines via an Electrostatic Attraction Effect Using (1,1-Diacetoxyiodo)benzene and a Halide Source

Xing

2015

J. Org. Chem.

View full text Add to dashboard Cite

The direct chlorination and bromination of (E)-enamines and (Z)-enamides to the corresponding (Z)-configurated α-chloroenamines, α-bromoenamines, and α-chloroenamides have been realized using NiCl2·6H2O or tetrabutyl ammonium bromide as a halide source and (1,1-diacetoxyiodo)benzene as an oxidant. The high stereoselective reactions which produce products with only (Z)-configurations can be attributed to the structure of the intermediates, the conformations of which are controlled by the electrostatic attractions between the positively charged nitrogen atoms and the oxygen atoms of the carbonyl group. This type of electrostatic effect has never been reported in olefin halogenations. For this reason, the three-membered bromonium ion is only a minor intermediate in the enamine bromination pathway. These methods open pathways to prepare α-chloroenamines and α-chloroenamides, which are not accessible via the currently used methods.

show abstract

Palladium-Catalyzed Intermolecular Dehydrogenative Aminohalogenation of Alkenes under Molecular Oxygen: An Approach to Brominated Enamines

Cited by 103 publications

References 70 publications

Palladium/Copper‐Cocatalyzed Oxidative Amidobrominations of Alkenes

Palladium/Copper‐Cocatalyzed Oxidative Amidobrominations of Alkenes

Modern Transition-Metal-Catalyzed Carbon–Halogen Bond Formation

Stereoselective Chlorination and Bromination of Enamides and Enamines via an Electrostatic Attraction Effect Using (1,1-Diacetoxyiodo)benzene and a Halide Source

Contact Info

Product

Resources

About