- Photocatalytic gem-Difluoroolefination Reactions by a Formal C?C Coupling/Defluorination Reaction with Diazoacetates
-
The photolysis of diazoalkanes to conduct singlet carbene transfer reactions of colored diazoalkanes has recently attracted significant interest in organic synthesis. Herein, we describe a photocatalytic approach that allows the access of triplet carbene
- Li, Fang,Pei, Chao,Koenigs, Rene M.
-
supporting information
(2021/12/14)
-
- Catalytic Ring Expansion of Activated Heteroarenes Enabled by Regioselective Dearomatization
-
Catalytic ring expansion of activated heteroarenes through 1,4-dearomative addition of diazoacetates was established for the construction of various fused azepines by an elaborate control of the reaction kinetics at each step. The use of a silver catalyst was essential to drive the overall reaction for generating the desired seven-membered azepines. Because of the excellent substrate scope and selectivity, the developed methodology presents an innovative approach for the synthesis of multifused azepines, which are biologically relevant molecules.
- Kim, Jiyoung,Yoo, Eun Jeong
-
supporting information
p. 4256 - 4260
(2021/06/28)
-
- Cross coupling of sulfonyl radicals with silver-based carbenes: A simple approach to β-carbonyl arylsulfones
-
A coupling reaction between sulfonyl radicals and silver-based carbenes has been well established. This simple radical-carbene coupling (RCC) process provided an efficient approach to a variety of β-carbonyl arylsulfones from sodium arylsulfinates and diazo compounds, and was characterized by wide substrate scope, easy scale-up, simple manipulation, accessible starting materials, and mild reaction conditions.
- Li, Jingjing,Lian, Pengcheng,Wan, Xiaobing,Wang, Hanghang,Zheng, Yonggao
-
supporting information
p. 2163 - 2169
(2020/03/27)
-
- Nickel-Catalyzed Transformation of Diazoacetates to Alkyl Radicals Using Alcohol as a Hydrogen Source
-
A nickel-catalyzed transformation of diazoacetates to α-carbonyl methylene radicals has been disclosed in the presence of hyperoxide using ethanol as a hydrogen source and solvent. This strategy is successfully applied in the formation of indolin-2-ones or 1,4-dicarbonyl compounds from acrylamides or enamides in moderate to good yields. These reactions undergo radical addition onto C-C double bonds followed by a cyclization/oxidation or an oxidation/hydrolysis process, respectively.
- Zhao, Jingjing,Li, Pan,Xu, Yaohua,Shi, Yixin,Li, Fuwei
-
supporting information
p. 9386 - 9390
(2019/11/28)
-
- Sulfonium ylide formation and subsequent C[sbnd]S bond cleavage of aromatic isopropyl sulfide catalyzed by hemin in aqueous solvent
-
Heme is an abundant and widely existed cofactor for a variety of metalloenzymes, whose broader use is generally impeded by its high instability and poor solubility. Here we report an environment-benign and efficient strategy for the sulfonium ylide formation and subsequent C[sbnd]S bond cleavage of aromatic isopropyl sulfides, which was catalyzed by hemin in assistance of Triton X-100. This aqueous catalytic system exhibited good functional group tolerance to a variety of sulfides and diazo esters. And the reaction mechanism was preliminarily proposed on the basis of designed reactions. Furthermore, the cleavage of C[sbnd]S bond followed by introducing a functional ester group to aromatic sulfides, may potentially be employed for the late stage functionalization (LSF) of organosulfur drug in the future.
- Yan, Xiaojing,Li, Chang,Xu, Xiaofei,He, Quan,Zhao, Xiaoyong,Pan, Yuanjiang
-
supporting information
p. 3081 - 3087
(2019/05/08)
-
- Interception of Secondary Amide Ylide with Sulfonamides: Catalyst-Controlled Synthesis of N-Sulfonylamidine Derivatives
-
A novel, secondary amide activation strategy has been developed through the in situ generation of ylides from amides and diazoacetates. Under the developed reaction conditions, Mn-catalyzed ylide formation and interception reaction by sulfonamide delivered a variety of N-sulfonylamidines. Notably, when highly active Zn(OTf)2 was used as the catalyst, further N-H insertion products were obtained. In contrast with traditional methods, our amide activation strategy is distinguished by accessible starting material, inexpensive catalyst, and broad substrate scope.
- Chen, Jijun,Long, Wenhao,Yang, Yonggang,Wan, Xiaobing
-
supporting information
p. 2663 - 2666
(2018/05/22)
-
- In situ generation of nitrile oxides from copper carbene and tert -butyl nitrite: Synthesis of fully substituted isoxazoles
-
Herein, we present a novel [3 + 2] cycloaddition reaction of β-keto esters with nitrile oxides, which were generated in situ from copper carbene and tert-butyl nitrite. This three-component reaction provides new methodology for the direct synthesis of fully substituted isoxazole derivatives, featuring mild reaction conditions, readily accessible starting materials and simple operation. The experimental studies and DFT calculations suggest that the reaction starts with the generation of the key intermediate nitrile oxides, followed by a [3 + 2] cycloaddition reaction of β-keto esters to give the final isoxazole products.
- Chen, Rongxiang,Ogunlana, Abosede Adejoke,Fang, Shangwen,Long, Wenhao,Sun, Hongmei,Bao, Xiaoguang,Wan, Xiaobing
-
supporting information
p. 4683 - 4687
(2018/07/06)
-
- In Situ Generation of Oxazole Ylide and Interception with Sulfonamide: Construction of Amidines Using Two Diazo Molecules
-
A novel generation of oxazole ylide and interception with sulfonamide have been well developed to construct fully substituted amidines. This copper-catalyzed four-component reaction incorporates two diazo molecules to target amidines and shows broad substrate scope, excellent functional groups tolerance and good to excellent yields.
- Chen, Jijun,Long, Wenhao,Zhao, Yanwei,Li, Haiyan,Zheng, Yonggao,Lian, Pengcheng,Wan, Xiaobing
-
supporting information
p. 857 - 865
(2018/07/31)
-
- Copper(II)-acid catalyzed cyclopropanation of 1,3-dienamides by electrophilic activation of α-aryl diazoesters
-
Copper(II)-acid catalyzed cyclopropanation of electron-rich alkenes, such as 1,3-dienamides, with α-aryl diazoesters are described. The reaction could be performed without rare metal catalysts, excess substrate, or the need for the slow addition of the diazoesters.
- Tayama, Eiji,Horikawa, Kouki,Iwamoto, Hajime,Hasegawa, Eietsu
-
supporting information
p. 3041 - 3044
(2014/05/20)
-
- Highly chemo- and stereoselective intermolecular coupling of diazoacetates to give cis-olefins by using Grubbs second-generation catalyst
-
Highly stereoselective formation of cis-2-ene-1,4-diesters by homo- and heterocoupling of α-diazoacetates in the presence of Grubbs second-generation catalyst is demonstrated. The dual reactivity of the catalyst in alkene metathesis and diazocoupling has been exploited in the synthesis of 12-26-membered macrocyclic dienyl dilactones by one-pot carbene dimerisation/ring-closing metathesis.
- Hodgson, David M.,Angrish, Deepshikha
-
p. 3470 - 3479
(2008/02/08)
-
- 63. Enantioselective Formation of Bicyclic Lactones by Rhodium-Catalyzed Intramolecular CH-Insertion Reactions
-
The decomposition of cyclohexyl diazoacetate (5a) in the presence of the chiral 4> catalyst leads to a 3:1 cis/trans mixture of bicyclic lactone 6a with an enantiomeric excess of 95-97percent (cis) and 90percent (trans).The conformationally rigid tert-butyl derivatives 5b and 5c afford, in the presence of the same catalyst, 6b and 6c, respectively, via insertion into the equatorial C-H bonds exclusively, with ee's of ca. 95percent.A remarkable degree of induction (92-95percent) results in the lactone 6g upon decomposition of 1-isopropyl-2-methylpropyl diazoacetate (5g).The diazoacetates derived from 1-methylcyclohexanol, cyclopentanol and 1-methylcyclopentanol (5d-f) afford under similar conditions insertion products with higher diastereoselectivity, but significantly lower enantioselectivity.Other dirhodium catalysts are less efficient.
- Mueller, Paul,Polleux, Philippe
-
p. 645 - 654
(2007/10/02)
-