99209-03-7Relevant articles and documents
MYOGLOBIN-BASED CATALYSTS FOR CARBENE TRANSFER REACTIONS
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Paragraph 0073; 00270, (2016/06/14)
Methods are provided for carrying out carbene transfer transformations such as olefin cyclopropanation reactions, carbene heteroatom-H insertion reactions (heteroatom = N, S, Si), sigmatropic rearrangement reactions, and aldehyde olefination reactions with high efficiency and selectivity by using a novel class of myoglobin-based biocatalysts. These methods are useful for the synthesis of a variety of organic compounds which contain one or more new carbon-carbon or carbon-heteroatom (N, S, or Si) bond. The methods can be applied for conducting these transformations in vitro (i.e., using the biocatalyst in isolated form) and in vivo (i.e., using the biocatalyst in a whole cell system).
Well-defined binuclear chiral spiro copper catalysts for enantioselective N-H insertion
Zhu, Shou-Fei,Xu, Bin,Wang, Guo-Peng,Zhou, Qi-Lin
supporting information; experimental part, p. 436 - 442 (2012/03/07)
An asymmetric N-H insertion of α-diazoesters with anilines catalyzed by well-defined copper complexes of chiral spiro bisoxazoline ligands was studied in detail. The copper-catalyzed asymmetric N-H insertion of a wide range of α-alkyl-α-diazoacetates with anilines was accomplished with excellent enantioselectivity (up to 98% ee) and provided an efficient method for the preparation of optically active α-amino acid derivatives. A correlation study of the electronic properties of the substrates with the enantioselectivity of the N-H insertion reaction supports a stepwise insertion mechanism, and the significant first-order kinetic isotope effect proves that the proton transfer is most likely the rate-limiting step. A binuclear chiral spiro copper catalyst having 14-electron copper centers, a trans coordination model, a perfect C2-symmetric chiral pocket, and significant Cu-Cu interaction was isolated and extensively studied. The novel structure of the binuclear chiral spiro copper catalyst leads to unique reactivity as well as enantioselectivity in the N-H insertion reaction.
Highly enantioselective insertion of carbenoids into NH bonds catalyzed by copper(I) complexes of binol derivatives
Hou, Zongrui,Wang, Jun,He, Peng,Wang, Jing,Qin, Bo,Liu, Xiaohua,Lin, Lili,Feng, Xiaoming
scheme or table, p. 4763 - 4766 (2010/09/15)
Figure Persentation Secondary amines do It tool Catalytic asymmetric insertion of a-diazoesters in the N-H bond of differently substituted amines has been successfully achieved (see scheme; M.S.=molecular sieves). For a wide substrate scope, excellent enantioselectivities (up to 98% ee) and high yields (up to 99%) were obtained under mild reaction conditions.
Synthesis of isatins with a chiral substituent at the nitrogen atom
Kurkin, Alexander V.,Bernovskaya, Anna A.,Yurovskaya, Marina A.
experimental part, p. 1500 - 1505 (2009/12/01)
(R)-Ethyl 2-(isatin-1-yl)propanoates 8a-c were prepared from the corresponding (R)-arylalanines by Sandmeyer's method in high yield and good enantioselectivity (up to 99%). The key step of the process is the Mitsunobu reaction.
Highly enantioselective insertion of carbenoids into N-H bonds catalyzed by copper complexes of chiral spiro bisoxazolines
Liu, Bin,Zhu, Shou-Fei,Zhang, Wei,Chen, Chao,Zhou, Qi-Lin
, p. 5834 - 5835 (2008/02/04)
A highly efficient copper-catalyzed asymmetric insertion of α-diazoesters into N-H bonds has been realized by using chiral spiro bisoxazoline ligands, affording α-amino acid derivatives in high yields with excellent enantioselectivities. Copyright
Synthesis of nonracemic 9-(1-methoxycarbonylethyl)-1,2,3,4-tetrahydrocarbazole
Kurkin,Nesterov,Karchava,Yurovskaya
, p. 1466 - 1477 (2007/10/03)
A new approach has been proposed to the synthesis of indole derivatives containing a chiral substituent at the nitrogen atom, comprizing Fischer indolization of phenylhydrazines with a chiral substituent at the α-nitrogen atom. The initial hydrazines were obtained by the alkylation (Mitsunobu reaction applying optically active esters of lactic acid) of anilines containing an electron-accepting substituent at the amino group. Subsequent removal of the activating acceptor grouping was realized by nitrosation of the chiral secondary aniline followed by reduction of the corresponding N-nitroso compound.
Amino Acids, 4 - Enantioselective Synthesis of N-Substituted α-Amino Carboxylic Acids from α-Hydroxy Carboxylic Acids
Effenberger, Franz,Burkard, Ulrike,Willfahrt, Joachim
, p. 314 - 333 (2007/10/02)
With primary and secondary amines, the (S)-α-(trifluoromethylsulfonyloxy) carboxylates (S)-3 afford in an SN2 reaction the N-substituted (R)-α-amino carboxylates (R)-5, (R)-9, and (R)-12, resp.The rates of α-substituted ethyl propionates decrease in the order of the substituents triflate (3a) >> bromide (8a) > mesylate (7a) >= tosylate (7b) > chloride (8b); in the reactions with amines, decreasing reactivity affords increasing racemisation and elimination as a consequence of the more drastic conditions which are required
