122845-63-0Relevant academic research and scientific papers
Asymmetric Petasis Borono-Mannich Allylation Reactions Catalyzed by Chiral Biphenols
Jiang, Yao,Schaus, Scott E.
supporting information, p. 1544 - 1548 (2017/02/05)
Chiral biphenols catalyze the asymmetric Petasis borono-Mannich allylation of aldehydes and amines through the use of a bench-stable allyldioxaborolane. The reaction proceeds via a two-step, one-pot process and requires 2–8 mole % of 3,3′-Ph2-BINOL as the optimal catalyst. Under microwave heating the reaction affords chiral homoallylic amines in excellent yields (up to 99 %) and high enantioselectivies (er up to 99:1). The catalytic reaction is a true multicomponent condensation reaction whereas both the aldehyde and the amine can possess a wide range of structural and electronic properties. Use of crotyldioxaborolane in the reaction results in stereodivergent products with anti- and syn-diastereomers both in good diastereoselectivities and enantioselectivities from the corresponding E- and Z-borolane stereoisomers.
A general aminocatalytic method for the synthesis of aldimines
Morales, Sara,Guijarro, Fernando G.,Garcia Ruano, Jose Luis,Cid, M. Belen
supporting information, p. 1082 - 1089 (2014/02/14)
A general and efficient biomimetic method for the synthesis of aldimines from aldehydes and compounds bearing the NH2 group in the presence of pyrrolidine as a catalyst has been developed. These organocatalytic reactions, based on the application of the concept of nucleophilic catalysis, proceed with outstanding yields in the absence of acids and metals under simple conditions and minimum experimental manipulation. The method has been mainly applied to the synthesis of N-sulfinyl and N-sulfonyl imines, but its general validity has been proven with the preparation of representative N-phosphinoyl, N-alkyl, and N-aryl imines. These unprecedented reactions, which presumably occur via iminium activation without requiring acidic conditions, are an interesting and competitive alternative to the classical methods for preparing aldimines.
Decarboxylative Mannich reactions
Boehm, Maximillian,Proksch, Kerstin,Mahrwald, Rainer
supporting information, p. 1046 - 1049 (2013/03/14)
p-Methoxyphenylimines obtained from enolizable aldehydes react in the absence of catalysts at room temperature with β-keto carboxylic acids through a decarboxylative Mannich reaction. The Mannich products were obtained with a high degree of anti selectivity. By use of chiral oxygen-containing aldehydes, operationally simple access to aminohydroxylated polyketide substructures is possible. The results of catalyst-free, decarboxylative Mannich reactions of enolizable imines are described. When the reaction is performed with imines obtained from chiral aldehydes, access to optically pure Mannich products is possible. Copyright
Tetrahydroquinolines and benzazepines through catalytic diastereoselective formal [4 + 2]-cycloaddition reactions between donor-acceptor cyclopropenes and imines
Truong, Phong M.,Mandler, Michael D.,Zavalij, Peter Y.,Doyle, Michael P.
supporting information, p. 3278 - 3281 (2013/07/26)
Regio- and diastereoselective Lewis acid catalyzed cycloaddition reactions between imines and donor-acceptor cyclopropenes generated from silyl-protected enoldiazoacetates provide direct access to stable cyclopropane-fused tetrahydroquinolines and, with cyclopropane ring opening under mild conditions, to 1H-benzazipine derivatives.
A modified and highly useful protocol for the Bronsted acid catalyzed, enantioselective, vinylogous Mannich reaction with aliphatic aldimines
Abels, Falko,Schneider, Christoph
experimental part, p. 4050 - 4058 (2012/01/06)
Highly enantioselective as well as diastereoselective catalytic vinylogous Mannich reactions have been accomplished for the first time with aliphatic straight-chain aldimines and O,O-silylketene acetals and furnish valuable synthetic building blocks in hi
Anti-tumor compounds, pharmaceutical compositions, methods for preparation thereof and for treatment
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, (2008/06/13)
The present invention is directed to novel taxanes useful as chemotherapeutic agents or their precursors. Processes for preparing the novel taxanes include coupling reactions, in the presence of a base, of baccatin of formula (III) or (IV) STR1 with β-lac
Anti-tumor compounds, pharmaceutical compositions, methods for preparation thereof and for treatment
-
, (2008/06/13)
The present invention is directed to novel taxanes useful as chemotherapeutic agents or their precursors. Processes for preparing the novel taxanes include coupling reactions, in the presence of a base, of baccatin of formula (III) or (IV) STR1 with β-lac
New and efficient approaches to the semisynthesis of taxol and its C-13 side chain analogs by means of β-lactam synthon method
Ojima, Iwao,Habus, Ivan,Zhao, Mangzhu,Zucco, Martine,Park, Young Hoon,Sun, Chung Ming,Brigaud, Thierry
, p. 6985 - 7012 (2007/10/02)
Highly efficient chiral ester enolate-imine condensation giving 3-hydroxy-4-aryl-β-lactams with excellent enantiomeric purity is successfully applied to the asymmetric synthesis of the enantiomerically pure taxol C-13 side chain, N-benzoyl-(2R,3S)-3-phenyl-isoserine and its analogs. (3R,4S)-N-benzoyl-3-(1-ethoxyethoxy)-4-phenyl-2-azetidinone readily derived from the 3-hydroxy-4-phenyl-β-lactam is coupled with protected baccatin IIIs, followed by deprotection to give optically pure taxol and 10-deacetyl-7,10-bis(Troc)-taxol in good yields. Fully assigned 1H, 13C, and 2D (COSY and HETCOR) NMR spectra of taxol thus synthesized are shown and discussed.
Preparation of Activated Imines and Their Condensation with Allylstannanes: Stereoselective Synthesis of 1,2-Amino Alcohols
Ciufolini, Marco A.,Spencer, George O.
, p. 4739 - 4741 (2007/10/02)
A modified Wadsworth-Emmons reaction affords hitherto inaccessible imines derived from aliphatic aldehydes and aromatic amines.Such highly activated imines condense rapidly and stereoselectively with oxygenated allylstannanes, at -78 deg C, under the infl
