68826-48-2Relevant academic research and scientific papers
Synthesis of Exocyclic Trisubstituted Alkenes via Nickel- Catalyzed Kumada-Type Cross-Coupling Reaction of gem- Difluoroalkenes with Di-Grignard Reagents
Dai, Wenpeng,Zhang, Xuxue,Zhang, Juan,Lin, Yingyin,Cao, Song
supporting information, p. 183 - 187 (2016/02/16)
A practical, nickel-catalyzed Kumada-type double cross-coupling reaction of gem-difluoroalkenes with 1,4- or 1,5-di-Grignard reagents was developed. The reaction proceeded efficiently at room temperature and a variety of cyclization products, arylmethylenecyclopentanes and arylmethylenecyclohexanes, were obtained in high to excellent yields, respectively.
Direct catalytic cross-coupling of alkenyllithium compounds
Hornillos, Valentn,Giannerini, Massimo,Vila, Carlos,Faans-Mastral, Martn,Feringa, Ben L.
, p. 1394 - 1398 (2015/02/19)
A catalytic method for the direct cross-coupling of alkenyllithium reagents with aryl and alkenyl halides is described. The use of a catalyst comprising Pd2(dba)3/XPhos allows for the stereoselective preparation of a wide variety of substituted alkenes in high yields under mild conditions. In addition (1-ethoxyvinyl)lithium can be efficiently converted into substituted vinyl ethers which, after hydrolysis, give readily access to the corresponding methyl ketones in a one pot procedure.
Selective reaction of π-allyl(alkyloxy)palladium(II) complexes toward β-decarbopalladation, β-dehydropalladation, and reductive elimination
Harayama, Hiroto,Kimura, Masanari,Tanaka, Shuji,Tamara, Yoshinao
, p. 8475 - 8478 (2007/10/03)
Depending on the kind of R1 and R2, cyclic carbonates 1, in the presence of 10 mol% of Pd(PPh3)4 and 10 equiv of paraformaldehyde, selectively undergo three types of reaction: 1 (R1, R2 ≠ H) give dienes 3 exclusively; 1 (R1 = R2 = H and R1 ≠H, R2 = H) furnish 6-vinyl-1,3- dioxanes 5 exclusively, while 1 (R1 = H, R2 ≠ H) give rise to 4-pentenyl formates 4 selectively (together with 3 as the minor products).
Subsituted 4-(2-alkenylsulfinyl)morpholines : preparation and conversion into the corresponding sulfinic acids and esters. Stereochemistry of olefin formation by hydrolytic desulfinylation of allylic sulfinamides.
Baudin, Jean-Bernard,Julia, Sylvestre
, p. 196 - 214 (2007/10/02)
By reaction with 4-(chlorosulfenyl)morpholine in the presence of triethylamine, several substituted allylic alcohols have been converted into the title sulfinamides.As a complementary method, the new α-lithio allylic sulfinamides have been prepared and efficiently alkylated with organic halides.The boron trifluoride-etherate catalyzed treatment of the allylic sulfinamides with simple saturated alcohols provided the corresponding alkyl sulfinates while propargylic and allylic alcohols opened a route to various α,α'-bis-unsaturated sulfones.Efficient conditions for the acid-catalyzed hydrolysis of allylic sulfinamides are described and some allylic sulfinic acids bearing an electron-withdrawing group were isolated.Smooth fragmentation of the homoconjugated sulfinic acids gave the corresponding (E)-olefins stereoselectively. - Key words: sigmatropic rearrangement / allylic sulfinamide / allylic sulfinic ester / organolithium derivative / sulfone / retro-ene reaction / sulfur dioxide elimination / stereochemistry
Stereochemistry of direct olefin formation from carbonyl compounds and lithiated heterocyclic sulfones
Baudin, J. B.,Hareau, G.,Julia, S. A.,Lorne, R.,Ruel, O.
, p. 856 - 878 (2007/10/02)
The conditions for the title reaction were studied for the 2-benzothiazole and 2-pyridine series and for some examples in the 2-pyrimidine series.The olefin preparations were generally observed to be more efficient for 2-BT-sulfone systems.From the data of the hundred cases studied, it can be concluded that (E)-olefins are obtained: (i) from saturated BT-sulfones and aromatic aldehydes; and (ii) from benzylic BT-sulfones and branched saturated aldehydes (isobutyraldehyde, pivalaldehyde) or α,β-ethylenic or aromatic aldehydes. (Z)-olefins arise: (i) fom propargylic BT-sulfones and saturated or aromatic aldehydes; and (ii) from allylic or benzylic Pyr-sulfones and saturated aldehydes.Possible mechanisms for this new olefination procedure were examined. - heteroaromatic sulfones, organolithium derivatives, intramolecular ipso reactions, stereochemistry, elimination, olefination.
A direct synthesis of olefins by reaction of carbonyl compounds with lithio derivatives of 2-[alkyl- or (2'-alkenyl)- or benzyl-sulfonyl]-benzothiazoles
Baudin,Hareau,Julia,Ruel
, p. 1175 - 1178 (2007/10/02)
During the title reaction, the lithium alkoxides formed as intermediates undergo an intramolecular addition to the neighboring C = N group followed an S to O benzothiazole transfer and simultaneous extrusion of sulfur dioxide and ejection of 2(3H)-benzothiazolone anion.
