79606-79-4Relevant academic research and scientific papers
A combined DFT and NMR investigation of the zinc organometallic intermediate proposed in the syn-selective tandem chain extension-aldol reaction of β-keto esters
Aiken, Karelle S.,Eger, Wilhelm A.,Williams, Craig M.,Spencer, Carley M.,Zercher, Charles K.
experimental part, p. 5942 - 5955 (2012/10/08)
The tandem chain extension-aldol (TCA) reaction of β-keto esters provides an α-substituted γ-keto ester with an average syn:anti selectivity of 10:1. It is proposed that the reaction proceeds via a carbon-zinc bound organometallic intermediate potentially bearing mechanistic similarity to the Reformatsky reaction. Evidence, derived from control Reformatsky reactions and a study of the structure of the TCA intermediate utilizing DFT methods and NMR spectroscopy, suggests the γ-keto group of the TCA intermediate plays a significant role in diastereoselectivity observed in this reaction. Such coordination effects have design implications for future zinc mediated reactions.
New pyrrole-based amino acids for the synthesis of peptidomimetic constrained scaffolds
Alongi, Maddalena,Minetto, Giacomo,Taddei, Maurizio
, p. 7069 - 7072 (2007/10/03)
A new family of pyrrole-based amino acids have been prepared through the microwave assisted Paal-Knorr reaction of 1-4 ketoesters derived from the corresponding β-ketoester with a functional homologation. The carboxylic group is located in position 3 of the pyrrole, whereas the amino group, protected with the Cbz moiety, is present on the side chain in positions 1 or 2. These compounds were used to prepare constrained oligopeptides.
Microwave-assisted Paal-Knorr reaction - Three-step regiocontrolled synthesis of polysubstituted furans, pyrroles and thiophenes
Minetto, Giacomo,Raveglia, Luca F.,Sega, Alessandro,Taddei, Maurizio
, p. 5277 - 5288 (2007/10/03)
An efficient and highly versatile synthesis of furans, pyrroles and thiophenes is described. Starting from commercially available or easily prepared β-keto esters, functional homologation provides differently substituted 1,4-diketones that can be transfor
Microwave-Assisted Paal-Knorr Reaction. A Rapid Approach to Substituted Pyrroles and Furans
Minetto, Giacomo,Raveglia, Luca F.,Taddei, Maurizio
, p. 389 - 392 (2007/10/03)
(Equation presented) An array of tetrasubstituted pyrroles (and trisubstituted furans) was obtained using a simple three-step procedure. Functional homologation of a β-ketoester with an aldehyde followed by oxidation gave a series of differently substitut
Tandem chain extension-aldol reaction: syn selectivity with a zinc enolate.
Lai,Zercher,Jasinski,Reid,Staples
, p. 4169 - 4171 (2007/10/03)
A tandem chain extension-aldol reaction was developed in which beta-keto esters are transformed to alpha-substituted-gamma-keto esters in an efficient zinc-mediated, one-pot reaction. The diastereoselectivity of the reaction ranged from good to excellent
A TITANOXYCYCLOPROPANE AS INTERMEDIATE IN A HIGHLY STEREOSELECTIVE HOMOALDOL TYPE ADDITION SYNTHESES OF CIS-SUBSTITUTED TETRAHYDROFURAN DERIVATIVES
Reissig, Hans-Ulrich,Holzinger, Hiltrud,Glomsda, Gabriele
, p. 3139 - 3150 (2007/10/02)
Reaction of methyl 2-siloxycyclopropanecarboxylate 4 with TiCl4 provides the unique titanoxycyclopropane 10 whose structure could be elucidated by means of NMR-spectroscopy.Its additions to aldehydes and acetophenone occur with high stereoselectivity to a
LEWIS-ACID-PROMOTED ADDITIONS OF CARBONYL COMPOUNDS TO DONOR-ACCEPTOR SUBSTITUTED CYCLOPROPANES: A NEW SYNTHESIS OF 2,3-DIHYDROFURANE DERIVATIVES
Reissig, Hans-Ulrich
, p. 2981 - 2984 (2007/10/02)
Methyl 2,3-dihydrofurane-3-carboxylates are synthesized from siloxycyclopropaneesters and ketones in the presence of TiCl4 with good yields.
