- Synthesis of Functionalized Silsesquioxane Nanomaterials by Rhodium-Catalyzed Carbene Insertion into Si?H Bonds
-
We report carbene insertion into Si?H bonds of polyhedral oligomeric silsesquioxanes (POSS) for the synthesis of highly functionalized siloxane nanomaterials. Dirhodium(II) carboxylates catalyze insertion of aryl-diazoacetates as carbene precursors to afford POSS structures containing both ester and aryl groups as orthogonal functional handles for further derivatization of POSS materials. Four diverse and structurally varied silsesquioxane core scaffolds with one, three, or eight Si?H bonds were evaluated with diazo reactants to produce a total of 20 new POSS compounds. Novel diazo compounds containing a fluorinated octyl group and boron-dipyrromethene (BODIPY) chromophore demonstrate the use of highly functionalized substrates. Transformations of aryl(ester)-functionalized POSS compounds derived from this method are demonstrated, including ester hydrolysis and Suzuki–Miyaura cross-coupling.
- Franz, Annaliese K.,Jagannathan, Jake R.,Targos, Karina
-
supporting information
(2021/11/27)
-
- Azide Radical Initiated Ring Opening of Cyclopropenes Leading to Alkenyl Nitriles and Polycyclic Aromatic Compounds
-
We report herein a radical-mediated amination of cyclopropenes. The transformation proceeds through a cleavage of the three-membered ring after the addition of an azide radical on the strained double bond and leads to tetrasubstituted alkenyl nitrile derivatives upon loss of N2. With 1,2-diaryl substituted cyclopropenes, this methodology could be extended to a one-pot synthesis of highly functionalized polycyclic aromatic compounds (PACs). This transformation allows the synthesis of nitrile-substituted alkenes and aromatic compounds from rapidly accessed cyclopropenes using only commercially available reagents.
- Muriel, Bastian,Waser, Jerome
-
supporting information
p. 4075 - 4079
(2021/01/18)
-
- Visible-light-promoted selective: O -alkylation of 2-pyridones with α-aryldiazoacetates
-
A visible-light-promoted O-H insertion reaction between 2-pyridones and α-aryldiazoacetates has been developed. Upon visible light irradiation, the reaction proceeds smoothly under mild and catalyst-free conditions. A wide scope of 2-pyridones and α-aryldiazoacetates are well tolerated, and various O-alkylated 2-pyridones are obtained with perfect selectivity and good functional group tolerance. A photoinduced radical process is probably responsible for the excellent selectivity. This journal is
- Yang, Jingya,Wang, Ganggang,Zhou, Hongyan,Li, Zhifeng,Ma, Ben,Song, Menghui,Sun, Rongxia,Huo, Congde
-
supporting information
p. 394 - 398
(2021/01/29)
-
- Tropylium-Catalyzed O-H Insertion Reactions of Diazoalkanes with Carboxylic Acids
-
Herein, we describe the application of a nonbenzenoid aromatic carbocation, namely tropylium, as an organic Lewis acid catalyst in O-H functionalization reactions of diazoalkanes with benzoic acids. The newly developed protocol is applicable to a wide range of diazoalkane and carboxylic acid substrates with excellent efficiency (43 examples, up to 99% yield).
- Empel, Claire,Nguyen, Thanh Vinh,Koenigs, Rene M.
-
supporting information
p. 548 - 553
(2021/01/26)
-
- Dirhodium(II)/Xantphos-Catalyzed Relay Carbene Insertion and Allylic Alkylation Process: Reaction Development and Mechanistic Insights
-
Although dirhodium-catalyzed multicomponent reactions of diazo compounds, nucleophiles and electrophiles have achieved great advance in organic synthesis, the introduction of allylic moiety as the third component via allylic metal intermediate remains a formidable challenge in this area. Herein, an attractive three-component reaction of readily accessible amines, diazo compounds, and allylic compounds enabled by a novel dirhodium(II)/Xantphos catalysis is disclosed, affording various architecturally complex and functionally diverse α-quaternary α-amino acid derivatives in good yields with high atom and step economy. Mechanistic studies indicate that the transformation is achieved through a relay dirhodium(II)-catalyzed carbene insertion and allylic alkylation process, in which the catalytic properties of dirhodium are effectively modified by the coordination with Xantphos, leading to good activity in the catalytic allylic alkylation process.
- Liang, Xinyi,Lu, Bin,Peng, Qian,Wang, Xiaoming,Wang, Zijian,Zhang, Jinyu
-
supporting information
p. 11799 - 11810
(2021/08/16)
-
- Erratum: Oxazaborolidinium Ion-Catalyzed Cyclopropanation of α-Substituted Acroleins: Enantioselective Synthesis of Cyclopropanes Bearing Two Chiral Quaternary Centers (J. Am. Chem. Soc. (2011) 133:51 (20708?20711) DOI: 10.1021/ja209270e)
-
Pages 20709 and 20710. In the published version of the paper, the trans:cis ratios of 2w and 2x were reversed. The revised results were confirmed by NOE experiments and comparison of the optical rotation data with reported values after transformation. The
- Gao, Lizhu,Hwang, Geum-Sook,Ryu, Do Hyun
-
supporting information
p. 6021 - 6022
(2021/05/13)
-
- Synthesis of Quinolines via the Metal-free Visible-Light-Mediated Radical Azidation of Cyclopropenes
-
We report the synthesis of quinolines using cyclopropenes and an azidobenziodazolone (ABZ) hypervalent iodine reagent as an azide radical source under visible-light irradiation. Multisubstituted quinoline products were obtained in 34-81% yield. The reaction was most efficient for 3-trifluoromethylcyclopropenes, affording valuable 4-trifluoromethylquinolines. The transformation probably proceeds through the cyclization of an iminyl radical formed by the addition of the azide radical on the cyclopropene double bond, followed by ring-opening and fragmentation.
- Smyrnov, Vladyslav,Muriel, Bastian,Waser, Jerome
-
supporting information
p. 5435 - 5439
(2021/07/21)
-
- Synthesis of Rhodium Complexes with Chiral Diene Ligands via Diastereoselective Coordination and Their Application in the Asymmetric Insertion of Diazo Compounds into E?H Bonds
-
A new method for the synthesis of chiral diene rhodium catalysts is introduced. The readily available racemic tetrafluorobenzobarrelene complexes [(R2-TFB)RhCl]2 were separated into two enantiomers via selective coordination of one of them with the auxiliary S-salicyl-oxazoline ligand. One of the resulting chiral complexes with an exceptionally bulky diene ligand [(R,R-iPr2-TFB)RhCl]2 was an efficient catalyst for the asymmetric insertion of diazoesters into B?H and Si?H bonds giving the functionalized organoboranes and silanes with high yields (79–97 %) and enantiomeric purity (87–98 % ee). The stereoselectivity of separation via auxiliary ligand and that of the catalytic reaction was predicted by DFT calculations.
- Ankudinov, Nikita M.,Chusov, Denis A.,Nelyubina, Yulia V.,Perekalin, Dmitry S.
-
supporting information
p. 18712 - 18720
(2021/07/20)
-
- Catalytic Asymmetric Darzens-Type Epoxidation of Diazoesters: Highly Enantioselective Synthesis of Trisubstituted Epoxides
-
Highly enantioselective Darzens-type epoxidation of diazoesters with glyoxal derivatives was accomplished using a chiral boron–Lewis acid catalyst, which facilitated asymmetric synthesis of trisubstituted α,β-epoxy esters. In the presence of a chiral oxazaborolidinium ion catalyst, the reaction proceeded in high yield (up to 99 %) with excellent enantio- and diastereoselectivity (up to >99 % ee and >20:1 dr, respectively). The synthetic potential of this method was illustrated by conversion of the products to various compounds such as epoxy γ-butyrolactone, tertiary β-hydroxy ketone and epoxy diester.
- Jeong, Hye-Min,Nam, Dong Guk,Ryu, Do Hyun,Shim, Su Yong
-
supporting information
p. 22236 - 22240
(2021/09/13)
-
- Catalytic Asymmetric Fluorination of Copper Carbene Complexes: Preparative Advances and a Mechanistic Rationale
-
The Cu-catalyzed reaction of substituted α-diazoesters with fluoride gives α-fluoroesters with ee values of up to 95 %, provided that chiral indane-derived bis(oxazoline) ligands are used that carry bulky benzyl substituents at the bridge and moderately bulky isopropyl groups on their core. The apparently homogeneous solution of CsF in C6F6/hexafluoroisopropanol (HFIP) is the best reaction medium, but CsF in the biphasic mixture CH2Cl2/HFIP also provides good results. DFT studies suggest that fluoride initially attacks the Cu- rather than the C-atom of the transient donor/acceptor carbene intermediate. This unusual step is followed by 1,2-fluoride shift; for this migratory insertion to occur, the carbene must rotate about the Cu?C bond to ensure orbital overlap. The directionality of this rotatory movement within the C2-symmetric binding site determines the sense of induction. This model is in excellent accord with the absolute configuration of the resulting product as determined by X-ray diffraction using single crystals of this a priori wax-like material grown by capillary crystallization.
- Buchsteiner, Michael,Fürstner, Alois,Jerabek, Paul,Lehmann, Christian W.,Martinez-Rodriguez, Luis,N?thling, Nils,Patzer, Michael,Pozo, Iago
-
supporting information
p. 2509 - 2515
(2020/02/26)
-
- Thermal Stability and Explosive Hazard Assessment of Diazo Compounds and Diazo Transfer Reagents
-
Despite their wide use in academia as metal-carbene precursors, diazo compounds are often avoided in industry owing to concerns over their instability, exothermic decomposition, and potential explosive behavior. The stability of sulfonyl azides and other diazo transfer reagents is relatively well understood, but there is little reliable data available for diazo compounds. This work first collates available sensitivity and thermal analysis data for diazo transfer reagents and diazo compounds to act as an accessible reference resource. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and accelerating rate calorimetry (ARC) data for the model donor/acceptor diazo compound ethyl (phenyl)diazoacetate are presented. We also present a rigorous DSC dataset with 43 other diazo compounds, enabling direct comparison to other energetic materials to provide a clear reference work to the academic and industrial chemistry communities. Interestingly, there is a wide range of onset temperatures (Tonset) for this series of compounds, which varied between 75 and 160 °C. The thermal stability variation depends on the electronic effect of substituents and the amount of charge delocalization. A statistical model is demonstrated to predict the thermal stability of differently substituted phenyl diazoacetates. A maximum recommended process temperature (TD24) to avoid decomposition is estimated for selected diazo compounds. The average enthalpy of decomposition (?"HD) for diazo compounds without other energetic functional groups is-102 kJ mol-1. Several diazo transfer reagents are analyzed using the same DSC protocol and found to have higher thermal stability, which is in general agreement with the reported values. For sulfonyl azide reagents, an average ?"HD of-201 kJ mol-1 is observed. High-quality thermal data from ARC experiments shows the initiation of decomposition for ethyl (phenyl)diazoacetate to be 60 °C, compared to that of 100 °C for the common diazo transfer reagent p-acetamidobenzenesulfonyl azide (p-ABSA). The Yoshida correlation is applied to DSC data for each diazo compound to provide an indication of both their impact sensitivity (IS) and explosivity. As a neat substance, none of the diazo compounds tested are predicted to be explosive, but many (particularly donor/acceptor diazo compounds) are predicted to be impact-sensitive. It is therefore recommended that manipulation, agitation, and other processing of neat diazo compounds are conducted with due care to avoid impacts, particularly in large quantities. The full dataset is presented to inform chemists of the nature and magnitude of hazards when using diazo compounds and diazo transfer reagents. Given the demonstrated potential for rapid heat generation and gas evolution, adequate temperature control and cautious addition of reagents that begin a reaction are strongly recommended when conducting reactions with diazo compounds.
- Green, Sebastian P.,Wheelhouse, Katherine M.,Payne, Andrew D.,Hallett, Jason P.,Miller, Philip W.,Bull, James A.
-
supporting information
p. 67 - 84
(2020/01/31)
-
- Diazo Activation with Diazonium Salts: Synthesis of Indazole and 1,2,4-Triazole
-
A donor/acceptor diazo activation strategy, processing via condensation using diazonium salts without the addition of any other catalysts or reagents, is reported. The diazenium intermediate was found to undergo cyclization to give indazoles in excellent yields. Alternatively, in the presence of nitriles, substituted 1,2,4-triazoles were obtained in good to excellent yields. This interesting diazenium route provides a new approach to achieve complex heterocycle synthesis under mild conditions.
- Li, Xuming,Ye, Xiaohan,Wei, Chiyu,Shan, Chuan,Wojtas, Lukasz,Wang, Qilin,Shi, Xiaodong
-
supporting information
p. 4151 - 4155
(2020/06/05)
-
- Cu(I)/chiral bisoxazoline-catalyzed enantioselective sommelet-hauser rearrangement of sulfonium ylides
-
Catalytic asymmetric thia-Sommelet-Hauser rearrangement of sulfonium ylides remains a great challenge due to its multistep reaction mechanism involving metal carbene formation, proton transfer, and [2,3]-sigmatropic rearrangement. In particular, the key problem of such reactions is the differentiation of the enantiotopic lone pair electrons of sulfur, which generates the sulfonium ylide intermediate bearing chirality on the sulfur atom. With a modified chiral bisoxazoline ligand, we developed a Cu(I)- catalyzed asymmetric thia-Sommelet-Hauser rearrangement with good to excellent enantioselectivities. Mechanistic studies provide insights into the details of the reaction mechanism.
- Wang, Jianbo,Li, Shu-Sen
-
supporting information
p. 12343 - 12358
(2020/11/10)
-
- Three-Component Synthesis of Isoquinoline Derivatives by a Relay Catalysis with a Single Rhodium(III) Catalyst
-
A rhodium(III)-catalyzed one-pot three-component reaction of N-methoxybenzamide, α-diazoester, and alkyne was developed, providing an alternative way to synthesize isoquinoline derivatives. Mechanistically, it is a relay catalysis, and the reaction occurred via successive O-alkylation and C-H activation processes, both of which were promoted by the same catalyst.
- Zhou, Chao,Jiang, Jijun,Wang, Jun
-
supporting information
p. 4971 - 4975
(2019/09/03)
-
- Iron-Catalyzed Carbene Insertion Reactions of α-Diazoesters into Si-H Bonds
-
An efficient iron-catalyzed carbene insertion reaction of α-diazo carbonyl compounds into the Si-H bond was developed. A wide range of α-silylesters was obtained in high yields (up to 99%) from α-diazoesters using a simple iron(II) salt as catalyst.
- Keipour, Hoda,Ollevier, Thierry
-
supporting information
p. 5736 - 5739
(2017/11/10)
-
- Enantioselective Palladium-Catalyzed Carbene Insertion into the N?H Bonds of Aromatic Heterocycles
-
C3-substituted indoles and carbazoles react with α-aryl-α-diazoesters under palladium catalysis to form α-(N-indolyl)-α-arylesters and α-(N-carbazolyl)-α-arylesters. The products result from insertion of a palladium-carbene ligand into the N?H bond of the aromatic N-heterocycles. Enantioselection was achieved using a chiral bis(oxazoline) ligand, in many cases with high enantioselectivity (up to 99 % ee). The method was applied to synthesize the core of a bioactive carbazole derivative in a concise manner.
- Arredondo, Vanessa,Hiew, Stanley C.,Gutman, Eugene S.,Premachandra, Ilandari Dewage Udara Anulal,Van Vranken, David L.
-
supporting information
p. 4156 - 4159
(2017/04/03)
-
- Rhodium- and non-metal-catalyzed approaches for the conversion of isoxazol-5-ones to 2,3-dihydro-6H-1,3-oxazin-6-ones
-
Two approaches were developed for the conversion of isoxazol-5-ones to 2,3-dihydro-6H-1,3-oxazin-6-ones. The first involves dirhodium-catalyzed reaction of aryl diazoacetates, leading to rhodium carbene intermediates that undergo insertion into the N-O bo
- Jurberg, Igor D.,Davies, Huw M.L.
-
supporting information
p. 5158 - 5161
(2017/11/06)
-
- The Rh(II)-catalyzed formal N-S bond insertion reaction of aryldiazoacetates into: N -phenyl-sulfenyl phthalimide
-
The Rh(ii)-catalyzed sulfur ylide [1,2]-rearrangement of carbenoids generated from aryldiazoacetates has been realized via N-S bond insertion, generating tertiary sulfides in moderate to excellent yields. This demonstrates the first use of the sulfur ylide [1,2]-rearrangement undergoing N-S bond insertion. This protocol could proceed smoothly with high regioselectivity, low catalyst loading (0.1 mol% Rh2(OAc)4), gram-scale reaction and broad substrate scope. And the product could be converted into glycine derivatives through simple procedures.
- Song, Zhuang,Wu, Yizhou,Xin, Tao,Jin, Chao,Wen, Xiaoan,Sun, Hongbin,Xu, Qing-Long
-
supporting information
p. 6079 - 6082
(2016/05/19)
-
- Silver-mediated direct trifluoromethoxylation of α-diazo esters: Via the -OCF3 anion
-
Silver-mediated direct trifluoromethoxylation of α-diazo esters and ketosteroid was disclosed. The reactions of alkyl α-diazo arylacetates with AgOCF3 or CF3SO2OCF3/AgF at -30 to 10 °C under a N2 atmosphere provided α-trifluoromethoxyl arylacetates in up to 90% yield, while alkyl α-diazo vinylacetates reacting with CF3SO2OCF3/AgF or AgOCF3 afforded γ-trifluoromethoxyl α,β-unsaturated esters in up to 94% yield. The α-diazo ketosteroid was also trifluoromethoxylated under the standard reaction conditions. This protocol allows for an effective and convenient access to a large number of synthetic building blocks, which are promising in the development of new functional OCF3-molecules.
- Zha, Gao-Feng,Han, Jia-Bin,Hu, Xiao-Qian,Qin, Hua-Li,Fang, Wan-Yin,Zhang, Cheng-Pan
-
supporting information
p. 7458 - 7461
(2016/06/14)
-
- Direct Synthesis of Chiral Allenoates from the Asymmetric CH Insertion of α-Diazoesters into Terminal Alkynes
-
The asymmetric CH insertion of α-diazoesters into 1-alkynes was achieved using chiral cationic guanidinium salts and copper(I) complexes. Optically active 2,4-disubstituted allenoates were generated under mild reaction conditions from various α-diazoesters and 1-alkynes in high yield (up to 99‰) and enantioselectivity (up to 97:3 e.r.). Control experiments excluded the possibility of an asymmetric isomerization of alkynoates. Salt down: The title reaction was achieved using chiral cationic guanidinium salts with copper(I) complexes. Optically active 2,4-disubstituted allenoates were generated under mild reaction conditions from various α-diazoesters and 1-alkynes in high yield and enantioselectivity. Control experiments excluded the possibility of an asymmetric isomerization.
- Tang, Yu,Chen, Quangang,Liu, Xiaohua,Wang, Gang,Lin, Lili,Feng, Xiaoming
-
supporting information
p. 9512 - 9516
(2015/08/11)
-
- Synthesis of Aryldiazoacetates through Palladium(0)-Catalyzed Deacylative Cross-Coupling of Aryl Iodides with Acyldiazoacetates
-
Palladium(0)-catalyzed deacylative cross-coupling of aryl iodides and acyldiazocarbonyl compounds can be achieved at room temperature under mild reaction conditions. The coupling reaction represents a highly efficient and general method for the synthesis of aryldiazocarbonyl compounds, which have found wide and increasing applications as precursors for generating donor/acceptor-substituted metallocarbenes.
- Ye, Fei,Wang, Chengpeng,Zhang, Yan,Wang, Jianbo
-
supporting information
p. 11625 - 11628
(2016/02/19)
-
- Catalytic enantioselective carbon insertion into the β-vinyl C-H bond of cyclic enones
-
Chiral oxazaborolidinium ion-catalyzed Csp2-H functionalization of enones using diazoacetate has been developed. Various β-substituted cyclic enones were synthesized in high yield (up to 99%) with high to excellent enantioselectivity (up to 99%
- Lee, Sung Il,Hwang, Geum-Sook,Ryu, Do Hyun
-
supporting information
p. 7126 - 7129
(2013/07/05)
-
- Catalytic carbon insertion into the β-vinyl C-H bond of cyclic enones with alkyl diazoacetates
-
The first example of the boron Lewis acid catalyzed Csp2-H functionalization of cyclic enones was achieved using diazoacetates. The insertion of the carbon atom of diazoacetates utilizes BF3? Et2O or a newly designed oxaza
- Lee, Sung Il,Kang, Byung Chul,Hwang, Geum-Sook,Ryu, Do Hyun
-
supporting information
p. 1428 - 1431
(2013/06/26)
-
- Cinchona alkaloids induce asymmetry in the insertion reaction of thermally generated carbenes into N-H bonds
-
Ammonium ylides generated in situ from phenyldiazoacetates and anilines undergo asymmetric N-H insertion reactions catalyzed by cinchona alkaloids (1 mol %), affording phenylglycines up to 74% ee.
- Saito, Hiroaki,Morita, Daisuke,Uchiyama, Taketo,Miyake, Muneharu,Miyairi, Shinichi
-
supporting information
p. 6662 - 6664
(2013/01/15)
-
- Oxazaborolidinium ion-catalyzed cyclopropanation of α-substituted acroleins: Enantioselective synthesis of cyclopropanes bearing two chiral quaternary centers
-
A catalytic synthetic route to highly functionalized chiral cyclopropane derivatives was developed by Michael-initiated cyclopropanation of α-substituted acroleins with aryl- and alkyl diazoacetates. In the presence of chiral (S)-oxazaborolidinium cation
- Gao, Lizhu,Hwang, Geum-Sook,Ryu, Do Hyun
-
supporting information; experimental part
p. 20708 - 20711
(2012/02/06)
-
- Ruthenium catalyzed directing group-free C2-selective carbenoid functionalization of indoles by α-aryldiazoesters
-
[Chemical equation presented] A directing group-free approach for C2-selective carbenoid functionalization of NH-indoles is presented. Using [RuCl2(p-cymene)]2 as catalyst and α-aryldiazoesters as carbenoid source, 2-alkylated indoles were obtained in up to 96% isolated yield. Similarly, a regioselective carbenoid functionalization of NH-pyrroles was also achieved.
- Chan, Wai-Wing,Yeung, Shing-Hin,Zhou, Zhongyuan,Chan, Albert S. C.,Yu, Wing-Yiu
-
supporting information; experimental part
p. 604 - 607
(2010/08/20)
-
- Construction of stereodefined 1,1,2,2-tetrasubstituted cyclopropanes by acid catalyzed reaction of aryldiazoacetates and α-substituted acroleins
-
Michael-initiated ring closure of aryldiazoacetates and α-substituted acroleins under acid catalysis offers a unique opportunity for the stereoselective formation of various tetrasubstituted cyclopropanes. The Royal Society of Chemistry.
- Hashimoto, Takuya,Naganawa, Yuki,Kano, Taichi,Maruoka, Keiji
-
p. 5143 - 5145
(2008/09/19)
-
- Catalytic Asymmetric C-H Activation of Alkanes and Tetrahydrofuran
-
Rhodium carbenoids derived from methyl aryldiazoacetates are capable of effective catalytic asymmetric C-H activation of a range of alkanes and tetrahydrofuran by a C-H insertion mechanism. Dirhodium tetrakis(S-(N-dodecylbenzenesulfonyl)prolinate) (Rh2(S-DOSP)4) catalyzed decomposition of methyl aryldiazoacetates in the presence of alkanes results in intermolecular C-H insertions with good control of regioselectivity, diastereoselectivity, and enantioselectivity. The carbenoids derived from methyl aryldiazoacetates are considerably more chemoselective than carbenoids derived from diazoacetates. They strongly favor C-H insertions into secondary and tertiary sites. Formation of side products due to carbene dimerization is not a major problem with rhodium carbenoids derived from aryldiazoacetates.
- Davies, Huw M. L.,Hansen, Tore,Churchill, Melvyn Rowen
-
p. 3063 - 3070
(2007/10/03)
-