145099-77-0Relevant academic research and scientific papers
Novel stereoselective synthesis of (Z)-α,β-unsaturated esters by hydrostannylation-Stille tandem reaction of alkynyl esters with aryl iodides
Li, Jianying,Yu, Yan,Cheng, Mingzhu,Cai, Mingzhong
, p. 637 - 639,3 (2020/07/30)
(Z)-α,β-Unsaturated esters can be stereoselectively synthesised in one pot under mild conditions and in good yields, by the hydrostannylation of alkynyl esters followed by Stille cross-coupling with aryl iodides.
ALKYL (E)- AND (Z)-2,3-DIBROMOPROPENOATES AS PRECURSORS TO 3-SUBSTITUTED ALKYL (E)- AND (Z)-2-BROMOPROPENOATES, 2,3-DISUBSTITUTED ALKYL (Z)- AND (E)-PROPENOATES AND SOME HETEROCYCLIC COMPOUNDS
Rossi, Renzo,Bellina, Fabio,Carpita, Adriano,Gori, Raffaele
, p. 381 - 392 (2007/10/02)
3-(1-alkynyl)- and 3-aryl-substituted alkyl (Z)- and (E)-2-bromopropenoates have been stereospecifically and regioselectively synthesized by Pd-catalyzed cross-coupling reactions between 1-alkynylzinc chlorides, arylzinc chlorides or aryltributylstannanes and alkyl (Z)- and (E)-2,3-dibromopropenoates, (Z)- and (E)-2, respectively.The catalyst precursor consisting of a mixture of Pd on carbon and 3.9 equivalents of AsPh3 as well as that obtained by treatment of Pd(OAc)2 with 4 equivalents of AsPh3 in THF at 60 deg C can conveniently replace Pd(PPh3)4 in the reactions between (Z)- or (E)-2 and aryl or 1-alkynylzinc halides.On the other hand, a representative alkyl (Z)-3-alkyl-2-bromopropenoate has been prepared by reaction of a 9-alkyl-9-BBN derivative with (Z)-2a in DMF solution, in the presence of K2CO3 and a catalytic quantity of PdCl2(dppf).Some applications demonstrate the synthetic utility of 3-aryl-substituted alkyl (Z)- and (E)-propenoates, (Z)- and (E)-4.Thus, ethyl (E)-2-bromo-3-propenoate, (E)-4e, represents a direct precursor to 3-bromocoumarin, 7, and compound (Z)-8, which is obtained by acidic hydrolysis of (Z)-4e, undergoes a Pd-catalyzed intramolecular carbonylation reaction, which affords 3-ethoxycarbonylcoumarin, 9, in high yield.Moreover, treatment of compounds (Z)- and (E)-4 with organozinc or organotin derivatives, in the presence of catalytic amounts of a suitable Pd catalyst, affords, stereospecifically and in satisfactory to excellent yields, trisubstituted α,β-unsaturated esters, (E)- and (Z)-10, respectively, which cannot be easily prepared in stereoisomerically pure form by classical procedures.One of these esters, i.e. compound (E)-10c, represents a direct precursor to an isoaurone, i.e. (E)-3- benzylidenebenzofuran-2-one, (E)-11.Finally, a representative stereodefined unsymmetrically 2,3-diaryl-disubstituted alkyl propenoate has been synthesized by a one-pot procedure involving two sequential palladium-catalyzed arylations of (Z)-2a.
Synthesis of Variously 2-Substituted Alkyl (Z)- and (E)-2-Alkenoates and (Z)- and (E)-α-Ylidene-γ-butyrolactones via Palladium-Mediated Cross-Coupling Reactions between Organostannanes and Organic Halides
Bellina, Fabio,Carpita, Adriano,Santis, Massimo De,Rossi, Renzo
, p. 12029 - 12046 (2007/10/02)
Stereoisomerically pure trisubstituted α,β-unsaturated ester of general formula 7 have been efficiently synthetized using two different protocols.The first one involves the palladium(0)/copper(I)-mediated cross-coupling reaction between alkyl (E)-2-tributylstannyl-2-alkenoates, (E)-2, and aryl or alkenyl iodides.The second protocol, which allows to prepare stereodefined 2-aryl, 2-methyl, 2-(1-alkenyl) as well as 2-acyl substituted α,β-unsaturated esters, is based on the cross-coupling reaction between easily available alkyl (Z)- or (E)-2-halo-2-alkenoates and organostannanes in NMP, in the presence of catalytic amounts of PdCl2(PhCN)2, AsPh3 and CuI. (Z)- and (E)-2-ethenyl substituted α,β-unsaturated esters prepared according to this procedure have been proven to be useful precursors to (Z)- and (E)-α-ylidene-γ-butyrolactones, (Z)- and (E)-8, respectively.
New Stereoselective Snytheses of Stereodefined 2-Substituted Alkyl 2-Alkenoates and Their Applications
Rossi, Renzo,Carpita, Adriano,Cossi, Paolo
, p. 8801 - 8824 (2007/10/02)
Stereoisomerically pure alkyl (E)-2-tributylstannyl-2-alkenoates, (E)-8, which are easily prepared by palladium-catalyzed reaction between tributylstannane and alkyl 2-alkynoates, 15, have been employed as precursors to stereodefined 2-(hetero)aryl substituted alkyl 2-alkenoates of general formula 9 as well as alkyl (E)-2-methyl-2-alkenoates, (E)-10, having very high stereoisomeric purity.One of these esters, i.e. ethyl (Z)-4-(tert-butyldimethylsilyloxy)-2-phenyl-2-butenoate, (Z)-9d, has been employed in a very simple and efficient synthesis of3-phenyl-5(H)-2-furanone, 12, a metabolite of an hypnotic drug.On the other hand, the procedure employed to prepare esters (E)-10, which involves a configurational inversion, has been used to prepare the (S)-enantiomer of (E)-2,4-dimethyl-2-hexenoic acid, (E)-13, a caste-specific substance of male carpenter ants in the genus Camponotus, as well as 98percent optically pure (S)(E)-4,6-dimethyl-4-octen-3-one, (S)(E)-14, an alarm pheromone component of ants in the genus Manica.
New and efficient procedures for the synthesis of stereodefined 2-(hetero) aryl and 2-methyl substituted alkyl 2-alkenoates having very high stereoisomeric purity
Rossi, Renzo
, p. 4495 - 4498 (2007/10/02)
Stereodefined 2-(hetero)aryl and 2-methyl substituted alkyl 2-alkenoates of general formulai and2 have been synthesized with a high degree of stereoselectivity as well as in good overall yields starting from alkyl 2-alkynoates,4.
