1617-22-7Relevant articles and documents
Reductive deoxygenation using hydridozirconium enolates: A new synthesis of α,β-unsaturated esters
Godfrey,Ganem
, p. 7461 - 7464 (1992)
An unusual new reaction of Cp2ZrHCl transforms β-ketoesters into α,β-unsaturated esters in one step and provides a useful alternative to the traditional, three-step process of reduction, mesylation/tosylation, and elimination.
Biocatalytic synthesis of chiral cyclic γ-oxoesters by sequential C-H hydroxylation, alcohol oxidation and alkene reduction
Brenna, Elisabetta,Crotti, Michele,Gatti, Francesco G.,Monti, Daniela,Parmeggiani, Fabio,Pugliese, Andrea,Tentori, Francesca
supporting information, p. 5122 - 5130 (2017/11/09)
A three-step biocatalytic procedure is described for the conversion of methyl and ethyl cyclopentene- and cyclohexenecarboxylates into both the enantiomers of the corresponding chiral 3-oxoesters, which are useful building blocks for the synthesis of active pharmaceutical ingredients. The allylic hydroxylation of the starting cycloalkenecarboxylates is carried out by using R. oryzae resting cells entrapped in alginate beads, in acetate buffer solution at 25 °C. The oxidation of the intermediate allylic alcohols to unsaturated ketones, performed by the laccase/TEMPO system, and the ene-reductase mediated hydrogenation of the alkene bond were carried out in the same reaction vessel in a sequential mode at 30 °C. Being entirely biocatalytic, our multistep procedure provides considerable advantages in terms of selectivity and environmental impact over reported chemical methods.
Direct ortho-thiolation of arenes and alkenes by nickel catalysis
Lin, Cong,Li, Danyang,Wang, Binjie,Yao, Jinzhong,Zhang, Yuhong
supporting information, p. 1328 - 1331 (2015/03/14)
The direct thiolation of arenes and alkenes with diaryl disulfides was developed by nickel catalysis. The reaction displayed exceptional compatibility with a wide range of functional groups to regioselectively give the diaryl sulfides and alkenyl sulfides in high yields.
Stereo- and chemoselective cross-coupling between two electron-deficient acrylates: An efficient route to (Z, E)-muconate derivatives
Hu, Xu-Hong,Zhang, Jian,Yang, Xiao-Fei,Xu, Yun-He,Loh, Teck-Peng
supporting information, p. 3169 - 3172 (2015/03/30)
A Ru-catalyzed direct oxidative cross-coupling reaction of acrylates was developed. It offers a straightforward and atom-economical protocol for the synthesis of functionalized (Z,E)-muconate derivatives in moderate to good yields with good stereo- and chemoselectivities. The conjugated muconates bearing differentiable terminal functionality can be selectively transformed into versatile synthetic intermediates widely used in organic synthesis.
Iridium-catalyzed direct C-H amidation with weakly coordinating carbonyl directing groups under mild conditions
Kim, Jinwoo,Chang, Sukbok
supporting information, p. 2203 - 2207 (2014/03/21)
An iridium-catalyzed direct C-H amidation of weakly coordinating substrates, in particular of those bearing ester and ketone groups, under very mild conditions has been developed. The observed high reaction efficiency was achieved by the combined use of acetic acid and lithium carbonate as additives. Copyright
Iridium(I)-catalyzed vinylic C-H borylation of 1-cycloalkenecarboxylates with bis(pinacolato)diboron
Sasaki, Ikuo,Doi, Hana,Hashimoto, Toshiya,Kikuchi, Takao,Ito, Hajime,Ishiyama, Tatsuo
, p. 7546 - 7548 (2013/08/23)
Ir(i)-catalyzed C-H borylation of 1-cycloalkenecarboxylic derivatives with bis(pinacolato)diboron affords various alkenylboronates with functional groups in excellent yields. This reaction was also used in a one-pot borylation/Suzuki-Miyaura cross-coupling procedure.
Isothiourea-mediated asymmetric O- to C-carboxyl transfer of oxazolyl carbonates: Structure-selectivity profiles and mechanistic studies
Joannesse, Caroline,Johnston, Craig P.,Morrill, Louis C.,Woods, Philip A.,Kieffer, Madeleine,Nigst, Tobias A.,Mayr, Herbert,Lebl, Tomas,Philp, Douglas,Bragg, Ryan A.,Smith, Andrew D.
, p. 2398 - 2408 (2012/03/27)
The structural motif within a series of tetrahydropyrimidine-based isothioureas necessary for generating high asymmetric induction in the asymmetric Steglich rearrangement of oxazolyl carbonates is fully explored, with crossover and dynamic 19F NMR experiments used to develop a mechanistic understanding of this transformation. Copyright
A mild, catalytic and efficient Nazarov cyclization mediated by phosphomolybdic acid
Murugan, Kaliyappan,Srimurugan, Sankareswaran,Chen, Chinpiao
supporting information; experimental part, p. 1127 - 1129 (2010/06/18)
A mild, selective and efficient Nazarov cyclization of divinyl ketones catalyzed by phosphomolybdic acid (PMA) is described. The process demonstrates a broad substrate scope with functional group tolerance under short reaction times. PMA supported on silica gel is more efficient than the bulk catalyst and is recycled up to three times without significant activity loss.
Efficient preparation of α,α-dialkyl-α-(phenylselanyl) acetates and α,β-unsaturated esters from the corresponding α,α-dialkyl-α-cyanoacetates by a lithium naphthalenide induced reductive selenenylation process
Ko, Yen-Chun,Zhu, Jia-Liang
, p. 3659 - 3665 (2008/09/19)
An array of α,α-dialkyl-α-(phenylselanyl)acetates has been synthesized very efficiently from readily available α,α- dialkyl-α-cyanoacetates, by use of lithium naphthalenide induced reductive α-selenenylation as a key operation. Moreover, the selanyl esters thus generated in situ could be converted further, in a one-pot treatment with hydrogen peroxide and acetic acid, into the corresponding α,β- unsaturated esters in moderate to high yields. The C=C bond formation was highly regio- and/or diastereoselective in some cases. Georg Thieme Verlag Stuttgart.
An expedient, stereoselective synthesis of highly functionalized cyclic compounds
Krawczyk, Ewa,Owsianik, Krzysztof,Skowronska, Aleksandra,Wieczorek, Michal,Majzner, Wieslaw
, p. 1753 - 1767 (2007/10/03)
New thiophosphates containing functionalized cyclic ketone derivatives as ligands have been stereoselectively (prepared from readily available starting materials. Full axial stereoselectivity of the NaBH)4 (reduction) of the carbonyl group in thiophosphates providing the corresponding thiols or sulfides has been demonstrated. The sulfides have been transformed into new functionalized cyclic Baylis-Hillman type adducts of defined configuration. The prospects for the useful synthetic application of these adducts appear to be very promising.
