Nucleophilic addition of tertiary propargylic amines to arynes followed by a [2,3]-sigmatropic rearrangement

2018 ◽  
Vol 54 (47) ◽  
pp. 6036-6039 ◽  
Author(s):  
Meng-Guang Zhou ◽  
Rui-Han Dai ◽  
Shi-Kai Tian
Keyword(s):  
Nucleophilic Addition ◽  
Conjugated Dienes ◽  
Sigmatropic Rearrangement ◽  
Mild Conditions ◽  
Convenient Access

Treatment of tertiary propargylic amines with 2-(trimethylsilyl)aryl triflates under mild conditions provides convenient access to amino-substituted allenes or conjugated dienes.

scholarly journals Copper-Catalyzed Synthesis of Axially Chiral Biaryls with Diaryliodonium Salts as Arylation Reagents

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3223
Author(s):  
Ji-Wei Zhang ◽  
Shao-Hua Xiang ◽  
Shaoyu Li ◽  
Bin Tan
Keyword(s):  
Amino Alcohols ◽  
Sigmatropic Rearrangement ◽  
Synthetic Route ◽  
Mild Conditions ◽  
Good Substrate ◽  
Diaryliodonium Salts ◽  
Axially Chiral

NOBIN and BINAM derivatives harboring biaryl frameworks are recognized as a class of important atropisomers with versatile applications. Here, we present an efficient synthetic route to access such compounds through copper-catalyzed domino arylation of N-arylhydroxylamines or N-arylhydrazines with diaryliodonium salts and [3,3]-sigmatropic rearrangement. This reaction features mild conditions, good substrate compatibility, and excellent efficiency. The practicality of this protocol was further extended by the synthesis of biaryl amino alcohols.

Synthesis of Non-C2 Symmetrical NOBIN-Type Biaryls Through a Cascade N-Arylation and [3,3]-Sigmatropic Rearrangement from O-Arylhydroxylamines and Diaryliodonium Salts

2021 ◽  
Author(s):  
Fengting Liu ◽  
Min Wang ◽  
Jiatong Qu ◽  
Haifeng Lu ◽  
Hongyin Gao
Keyword(s):  
Sigmatropic Rearrangement ◽  
Mild Conditions ◽  
Diaryliodonium Salts

We developed herein a regioselective construction of non-C2 symmetrical NOBIN-type biaryls through a cascade N-arylation and [3,3]-sigmatropic rearrangement from O-arylhydroxylamines and diaryliodonium salts under mild conditions. The employment of copper...

scholarly journals Organocatalytic enantioselective dearomatization of thiophenes by 1,10-conjugate addition of indole imine methides

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xingguang Li ◽  
Meng Duan ◽  
Peiyuan Yu ◽  
K. N. Houk ◽  
Jianwei Sun
Keyword(s):  
Hydrogen Bonding ◽  
Phosphoric Acid ◽  
Nucleophilic Addition ◽  
Acid Catalysis ◽  
Conjugate Addition ◽  
Mild Conditions ◽  
Rapid Construction ◽  
Chiral Phosphoric Acid ◽  
Cyclic Molecules ◽  
Selectivity Control

AbstractCatalytic asymmetric dearomatization (CADA) is a powerful tool for the rapid construction of diverse chiral cyclic molecules from cheap and easily available arenes. This work reports an organocatalytic enantioselective dearomatization of substituted thiophenes in the context of a rare remote asymmetric 1,10-conjugate addition. By suitable stabilization of the thiophenyl carbocation with an indole motif in the form of indole imine methide, excellent remote chemo-, regio-, and stereocontrol in the nucleophilic addition can be achieved with chiral phosphoric acid catalysis under mild conditions. This protocol can be successfully extended to the asymmetric dearomatization of other heteroarenes including selenophenes and furans. Control experiments and DFT calculations demonstrate a possible pathway in which hydrogen bonding plays an important role in selectivity control.

Synthesis of Potential Anticancer 1-(1H-Indol-3-yl)isoquinolines by Silver Nitrate Mediated Tandem Reactions of 2-Alkynyl­benzaldehyde Azines and Indoles

Synlett ◽  
2018 ◽  
Vol 29 (06) ◽  
pp. 773-778 ◽  
Author(s):  
Yun-Hui Zhao ◽  
Zhihua Zhou ◽  
Yong-Cheng Ma ◽  
Yueyang Luo ◽  
Yingli Zhu ◽  
...  
Keyword(s):  
Silver Nitrate ◽  
Nucleophilic Addition ◽  
Bond Cleavage ◽  
Domino Reaction ◽  
Reference Compound ◽  
Lead Compounds ◽  
Mild Conditions ◽  
Antitumor Compounds ◽  
Interesting Class

Novel antitumor compounds featuring isoquinoline and indole moieties were synthesized by a silver nitrate promoted domino reaction involving intramolecular cyclization, nucleophilic addition of indole, and subsequent N–N bond cleavage. The transformation from readily available starting materials into an interesting class of indole-substituted isoquinolines was completed under mild conditions and by simple operations in moderate to good yields. The antitumor activity of these compounds in vitro was significantly greater than that of a reference compound, 5-fluorouracil. The products might serve as new lead compounds for drugs for the treatment of cancer.

Gold-Catalyzed Cyclization of O-Propargyl Carbamates under Mild Conditions: A Convenient Access to 4-Alkylidene-2-oxazolidinones.

ChemInform ◽  
2007 ◽  
Vol 38 (15) ◽  
Author(s):  
Stefanie Ritter ◽  
Yoshikazu Horino ◽  
Johann Lex ◽  
Hans-Guenther Schmalz
Keyword(s):  
Mild Conditions ◽  
Convenient Access

Highly selective difluoromethylations of β-keto amides with TMSCF2Br under mild conditions

Synlett ◽  
2021 ◽  
Author(s):  
yakun wang ◽  
Shuaifei Wang ◽  
Conghui Zhang ◽  
Ting Zhao ◽  
Yanqin Hu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Amino Alcohol ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Mild Conditions ◽  
Convenient Access

Without employing any transition metal and other additives, efficient methods for selective difluoromethylations of β-keto amides with TMSCF2Br reagent have been developed under mild conditions. This protocol allows a convenient access to various α-difluoromethyl β-keto amides with excellent yields (up to 93%) and high C/O regioselectivities (up to 99:1). The C/O selectivity of β-keto amides could be easily reversed and controlled by simply changing the base. This protocol can be easily scaled up and the C-difluoromethylation product could be reduced into CF2H contained amino-alcohol derivatives. Moreover, the first enantioselective electrophilic difluoromethylation of β-keto amides has been achieved by phase-transfer catalysis.

scholarly journals Highly selective difluoromethylations of β-keto amides with TMSCF2Br under mild conditions

2021 ◽  
Author(s):  
Yakun Wang ◽  
Shuaifei Wang ◽  
Conghui Zhang ◽  
Ting Zhao ◽  
Yanqin Hu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Amino Alcohol ◽  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Mild Conditions ◽  
Convenient Access

Without employing any transition metal and other additives, efficient methods for selective difluoromethylations of β-keto amides with TMSCF2Br reagent have been developed under alkaline and open-air conditions. This protocol allows a convenient access to various α-difluoromethyl β-keto amides with excellent yields (up to 93%) and high C/O regioselectivities (up to 99:1). The C/O selectivity of β-keto amides could be easily reversed and controlled by simply changing the base. This protocol can be easily scaled up and the C-difluoromethylation product could be reduced into amino-alcohol derivatives. Moreover, the first enantioselective electrophilic difluoromethylation of β-keto amides has been achieved by phase-transfer catalysis.

scholarly journals Phosphine/Photoredox Catalyzed anti-Markovnikov Hydroamination of Olefins with Primary Sulfonamides via a-Scission from Phosphoranyl Radicals

2021 ◽  
Author(s):  
Alex Chinn ◽  
Kassandra Sedillo ◽  
Abigail Doyle
Keyword(s):  
Radical Cation ◽  
Catalytic System ◽  
Nucleophilic Addition ◽  
Synthetic Chemistry ◽  
Radical Intermediate ◽  
Mild Conditions ◽  
Direct Formation ◽  
Phosphoranyl Radical ◽  
New Strategies

New strategies to access radicals from common feedstock chemicals hold the potential to broadly impact synthetic chemistry. We report a dual phosphine and photoredox catalytic system that enables direct formation of sulfonamidyl radicals from primary sulfonamides. The method is proposed to proceed via -scission of the sulfonamidyl radical from a phosphoranyl radical intermediate, generated upon sulfonamide nucleophilic addition to a phosphine radical cation. As compared to the recently well-explored β-scission chemistry of phosphoranyl radicals, this strategy is applicable to activation of N-based nucleophiles and is catalytic in phosphine. We highlight application of this activation strategy to an intermolecular anti-Markovnikov hydroamination of unactivated olefins with primary sulfonamides. A range of structurally diverse secondary sulfonamides can be prepared in good to excellent yields under mild conditions.

Efficient [3,3]-Sigmatropic Rearrangement Accelerated by a Trifluoroacetyl Group: Synthesis of Benzofurans under Mild Conditions.

ChemInform ◽  
2003 ◽  
Vol 34 (22) ◽  
Author(s):  
Okiko Miyata ◽  
Norihiko Takeda ◽  
Yoshiaki Morikami ◽  
Takeaki Naito
Keyword(s):  
Sigmatropic Rearrangement ◽  
Mild Conditions
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