34757-14-7Relevant academic research and scientific papers
Catalytic Asymmetric Homologation of Ketones with α-Alkyl α-Diazo Esters
Tan, Fei,Pu, Maoping,He, Jun,Li, Jinzhao,Yang, Jian,Dong, Shunxi,Liu, Xiaohua,Wu, Yun-Dong,Feng, Xiaoming
supporting information, p. 2394 - 2402 (2021/02/16)
The homologation of ketones with diazo compounds is a useful strategy to synthesize one-carbon chain-extended acyclic ketones or ring-expanded cyclic ketones. However, the asymmetric homologation of acyclic ketones with α-diazo esters remains a challenge due to the lower reactivity and complicated selectivity. Herein, we report the enantioselective catalytic homologation of acetophenone and related derivatives with α-alkyl α-diazo esters utilizing a chiral scandium(III) N,N′-dioxide as the Lewis acid catalyst. This reaction supplies a highly chemo-, regio-, and enantioselective pathway for the synthesis of optically active β-keto esters with an all-carbon quaternary center through highly selective alkyl-group migration of the ketones. Moreover, the ring expansion of cyclic ketones was accomplished under slightly modified conditions, affording a series of enantioenriched cyclic β-keto esters. Density functional theory calculations have been carried out to elucidate the reaction pathway and possible working models that can explain the observed regio- and enantioselectivity.
Enantioselective Palladium-Catalyzed Carbene Insertion into the N?H Bonds of Aromatic Heterocycles
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)
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.
Iron-Catalyzed Carbene Insertion Reactions of α-Diazoesters into Si-H Bonds
Keipour, Hoda,Ollevier, Thierry
supporting information, p. 5736 - 5739 (2017/11/10)
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.
Asymmetric N-H Insertion of secondary and primary anilines under the catalysis of palladium and chiral guanidine derivatives
Zhu, Yin,Liu, Xiaohua,Dong, Shunxi,Zhou, Yuhang,Li, Wei,Lin, Lili,Feng, Xiaoming
supporting information, p. 1636 - 1640 (2014/03/21)
Efficient enantioselective N-H insertion reactions of secondary and primary anilines were catalyzed by palladium(0) in combination with chiral guanidine derivatives. A broad range of substituted anilines were tolerated, and the corresponding products were obtained in high yield (up to 99 %) with good enantioselectivity (up to 94 % ee) under mild reaction conditions. The N-H insertion mechanism was examined by the study of kinetic isotope effects, control experiments, HRMS, and spectroscopic analysis. Hidden talents: Chiral guanidine derivatives were developed as useful ligands for the enantioselective insertion of carbenoids into the N-H bonds of secondary and primary anilines in combination with palladium(0), which was not previously known to promote asymmetric N-H insertion (see scheme; dba=dibenzylideneacetone). The N-H insertion mechanism was examined by kinetic isotope studies, control experiments, HRMS, and spectroscopic analysis. Copyright
Continuous-flow generation of diazoesters and their direct use in S-H and P-H insertion reactions: Synthesis of α-sulfanyl, α-sulfonyl, and α-phosphono carboxylates
Bartrum, Hannah E.,Blakemore, David C.,Moody, Christopher J.,Hayes, Christopher J.
, p. 2276 - 2282 (2013/04/10)
The synthesis of α-sulfanyl, α-sulfonyl, and α-phosphono carboxylates has been achieved using a two-step procedure involving the in-flow generation of diazoesters from sulfonylhydrazones, via Bamford-Stevens elimination, and then subsequent S-H, sulfinate
Catalytic asymmetric insertion of diazoesters into Aryl-CHO bonds: Highly enantioselective construction of chiral all-carbon quaternary centers
Gao, Lizhu,Kang, Byung Chul,Ryu, Do Hyun
supporting information, p. 14556 - 14559 (2013/10/22)
This paper describes a catalytic enantioselective route to synthesize functionalized all-carbon quaternary acyclic systems via a boron Lewis acid-promoted formal C-C insertion of diazoesters into aryl-CHO bonds. In the presence of chiral (S)-oxazaborolidinium cation 1d as a catalyst, the reaction proceeded in good yield (up to 83%) with good regioselectivity (up to 88:12) and excellent enantioselectivity (up to 99% ee). The synthetic potential of this method was illustrated by conversion of the products to both α-and β-amino esters.
Rapid access to α-alkoxy and α-amino acid derivatives through safe continuous-flow generation of diazoesters
Bartrum, Hannah E.,Blakemore, David C.,Moody, Christopher J.,Hayes, Christopher J.
supporting information; experimental part, p. 9586 - 9589 (2011/10/08)
Microreactors: A highly efficient continuous-flow process has been developed for the synthesis of diazoesters from arylsulfonylhydrazones by means of in-flow Bamford-Stevens reactions. Furthermore, a range of α-alkoxy and α-amino acid derivatives have bee
Desymmetrizing asymmetric ring expansion of cyclohexanones with α-diazoacetates catalyzed by chiral aluminum Lewis acid
Hashimoto, Takuya,Naganawa, Yuki,Maruoka, Keiji
supporting information; experimental part, p. 8834 - 8837 (2011/08/03)
Chiral aluminum Lewis acid catalyst composed of Me3Al and 3,3′-bis(trimethylsilyl)-BINOL in a 2:1 ratio was found to promote novel catalytic asymmetric ring expansion of cyclohexanone with α-substituted α-diazoacetates to give seven-membered rings with an all-carbon quaternary center. Application of this strategy to 4-substituted cyclohexanones opened up a novel way for the catalytic desymmetrizing asymmetric construction of cycloheptanones bearing remote α,δ-chiral centers.
Attempts of arsirane synthesis by addition of diazocompounds with arsaalkenes
Kabbab, Souad Himdi,Hamelin, Jack
, p. 2755 - 2758 (2007/10/02)
The reaction of ethyl diazoacetate with arsaalkenes 8 and 9, leads to diazaarsole 3 and diazocompounds 10 and 11. Diphenyldiazomethane addition follows a different course leading to alkenes 23 and 24, possibly through a transient arsirane.
Thermolysis and Photolysis of Some 5-Amino-4-methoxycarbonyl-Δ2-1,2,3-triazolines
Bourgois, J.,Mathieu, A.,Texier, F.
, p. 513 - 515 (2007/10/02)
Thermolysis of 5-amino-4-methyl-4-methoxycarbonyl-Δ2-1,2,3-triazolines leads to amidines and 1-methoxycarbonyl diazoethane.If the N1 substituent is a tosyl or benzoyl group, the corresponding triazoline is not isolated, the azide addition to the olefin gives directly the thermolysis products at room temperature.Triazoline photolysis leads to amino aziridines which are azomethine ylids.
