79238-23-6Relevant academic research and scientific papers
Divergent Reactivity of α,α-Disubstituted Alkenyl Hydrazones: Bench Stable Cyclopropylcarbinyl Equivalents
Ritchie, Nina F. C.,Wilkerson-Hill, Sidney M.,Zahara, Adam J.
, (2022/02/14)
Herein we report the divergent reactivity of 2,2-dialkyl-3-(E)-alkenyl N-tosylhydrazones using Pd-catalyzed cross-coupling conditions, which enable the Z-selective synthesis of 3-aryl-1,4-dienes and gem-dialkyl vinylcyclopropanes. We found that the dialky
Efficient Access to All-Carbon Quaternary and Tertiary α-Functionalized Homoallyl-type Aldehydes from Ketones
Pace, Vittorio,Castoldi, Laura,Mazzeo, Eugenia,Rui, Marta,Langer, Thierry,Holzer, Wolfgang
, p. 12677 - 12682 (2017/09/08)
β,γ-Unsaturated aldehydes with all-carbon quaternary or tertiary α-centers were rapidly assembled from ketones through a unique synthetic operation consisting of 1) C1 homologation, 2) Lewis acid mediated epoxide–aldehyde isomerization, and 3) electrophilic trapping. The synthetic equivalence of a vinyl oxirane and a β,γ-unsaturated aldehyde is the key concept of this previously undisclosed tactic. Mechanistic studies and labeling experiments suggest that an aldehyde enolate is a crucial intermediate. The homologating carbenoid formation plays a critical role in determining the chemoselectivity.
Oxidative C-C bond cleavage of aldehydes via visible-light photoredox catalysis
Sun, Hongnan,Yang, Chao,Gao, Fei,Li, Zhe,Xia, Wujiong
, p. 624 - 627 (2013/04/23)
The visible-light mediated oxidative C-C bond cleavage of aldehydes has been achieved in good yields at ambient temperature and open to air using Ru(bpy)3Cl2 (bpy = 2,2′-bipyridine) as the photoredox catalyst. Moreover, we further demonstrated the application in a tandem Michael/oxidative C-C bond cleavage reaction.
Nucleophilic Addition to Vinylketenimine Complexes. The Asymmetric Synthesis of Carbon Quaternary Centres
Richards, Christopher J.,Thomas, Susan E.
, p. 143 - 160 (2007/10/02)
Addition of alkyl-lithium reagents to (vinylketenimine)tricarbonyliron(0) complexes generates compounds containing carbon quaternary centres.The major products from these reactions are either amides or aldehydes depending upon the conditions employed.Dias
PHOTOCHEMISTRY OF β,γ-UNSATURATED KETONES - V ; THE DIRECT IRRADIATION OF SOME γ-PHENYL β;γ-ENONES
Weerdt, Anton J. A. Van Der,Cerfontain, Hans
, p. 2121 - 2130 (2007/10/02)
The photochemistry of some members of the two series of γ-phenyl substituted acyclic β,γ-unsaturated ketones 1 and 2 upon direct irradiation with λ 310 nm has been investigated, viz 1c-1h and 2b+2c.The alkyl substituted (E)-5-phenyl-4-penten-2-ones 1c-1h yield the corresponding 1,3-acyl shift products and (Z)-isomers, and 1g and 1h in addition two decarbonylated products. 2b only yields the (Z)-isomer and some benzaldehyde, but 2c yields the 1,3-acyl shift product, the ODPM product, three hydrocarbons formed by disproportionation of the allyl radical, and some benzaldehyde.The β-phenyl β,γ-UK 3a proved to be photostable.The 1,3-acyl shift products of 1c-1h result mainly from the singlet excited state in a cage radical process.The exclusive formation of the (E)-configuration of the 1,3-acyl shift product is explained in terms of conformational preference of the intermediate allyl radical.It is proposed that the formation of the (Z)-isomer proceeds from 1T(?-?*) which is populated according to .Evidence is presented which supports the proposed mechanism.The β,γ-UK 2b containing a benzoyl moiety leads to a higher degree of (E)-(Z) isomerization than the corresponding 1d which has an acetyl moiety.The triplet energies of (E)- and (Z)-1h are 56 and ca 70 kcal/mol respectively.
