Synthetic methodologies for carbo-substituted conjugated dienes

Abstract

We report the observation of changes in the wave turbulence properties of gravitycapillary surface waves due to a finite-depth effect. When the fluid depth is decreased, a hump is observed on the wave spectrum in the capillary regime at a scale that depends on the depth. The possible origin of this hump is discussed. In the gravity regime, the wave spectrum still shows a power law but with an exponent that strongly depends on the depth. A change in the scaling of the gravity spectrum with the mean injected power is also reported. Finally, the probability density function of the wave amplitude rescaled by its rms value is found to be independent of the fluid depth and to be well described by a Tayfun distribution.

Cu/Pd‐Catalyzed Cascade Reactions of Cyclic Diaryliodoniums and Alkynes – Access to Fluorenes with Conjugate Enynes/Dienes

“…Similarly, conjugate dienes are valuable products or intermediates in organic chemistry 11. Although numerous methods are available to prepare di‐ or trisubstituted dienes, effective methods to prepare more highly substituted dienes are limited 12…”

A Diverted Aerobic Heck Reaction Enables Selective 1,3-Diene and 1,3,5-Triene Synthesis through C–C Bond Scission

“…Substituted 1,3-dienes are common synthetic building blocks featured in a wide array of complexity-building catalytic transformations, including recently developed asymmetric hydrofunctionalizations, 1 difunctionalizations, 2 C−H functionalizations, 3 cycloadditions, 4 and cross-coupling. 5 Preparations of 1,3-dienes, 1-aryl-1,3-dienes being a particularly prevalent subset in modern catalytic methods, classically involve disconnections at the central sigma bond of the diene, 6 such as through Mizoroki-Heck reactions, cross-coupling, 7,8 and ene-yne metathesis, 9 or disconnection at the double bond in the case of Wittig-type olefinations (Scheme 1, left). 10 Drawbacks of these approaches include functional group compatibility with strongly basic organometallic reagents or, more importantly, limited structural diversity in commercial starting materials (i.e., styrenyl halides or cinnamaldehydes).…”

Regioselective Synthesis of 2-Acylbutadienes from β,γ-Unsaturated Ketones

“…The structures of all synthesized dienes 3, including the configurational assignment and the location of the substituents, were unambiguously proven by 1 H, 13 C, and 2D (NO-ESY, 1 H-13 C HSQC, 1 H-13 C HMBC) NMR spectroscopy. For example, in the 2D NOESY spectra of 3aa (Figure 1), crosspeaks were observed between the signals of proton at the C 1′ and protons at the ortho-position of the benzoyl moiety for E,E-isomer of 3aa, while for Z,E-isomer of 3aa crosspeaks between the signals of proton at the C 1′ and protons at the C 3 and C 4 were detected.…”