616216-91-2

Upstream product

• 26260-02-6 2-iodobenzaldehyde 
• 4336-70-3 (cyanomethyl)triphenylphosphonium chloride 
• 16640-68-9 cyanomethylene triphenylphosphorane 

Relevant academic research and scientific papers

Application of the palladium-catalyzed borylation/Suzuki coupling (BSC) reaction to the synthesis of biologically active biaryl lactams

The palladium-catalyzed, two-step, one-pot borylation/Suzuki coupling (BSC) reaction was developed to synthesize sterically hindered 2,2′-disubstituted biphenyl and phenyl-indole compounds in a short, simple, and efficient manner from two easily accessible aryl halides. High yields can be obtained by choosing properly both components according to their rough electronic properties. The illustration of the utility of this method was provided by the solution and solid-phase synthesis of seven- or eight-membered biphenyl lactams 5a-e, as well as paullone 3a. These compounds exhibit moderate albeit significant cytotoxicities and may serve as structural models for future medicinal chemistry developments.

Photocatalytic E → Z isomerization of polarized alkenes inspired by the visual cycle: Mechanistic dichotomy and origin of selectivity

Iteratively executed with exquisite spatial and temporal control, the selective isomerization of polarized alkenes underpins a plethora of complex biological processes ranging from natural product biosynthesis through to the mammalian visual cycle. However, nature's proficiency conceals the inherent difficulties in replicating this contrathermodynamic transformation in the laboratory. Recently, we disclosed the first highly Z-selective isomerization of polarized alkenes, employing the cinnamoyl chromophore as a retinal surrogate under UV-irradiation (402 nm) with (-)-riboflavin (Vitamin B2) as an inexpensive, organic photocatalyst (J. Am. Chem. Soc. 2015, 137, 11254-11257). This study was inspired by the propensity of crystalline (-)-riboflavin in the eyes of vertebrates to invert the intrinsic directionality of retinal isomerization. Herein, we extend this methodology to include a bioinspired, catalytic E → Z isomerization of α,β-unsaturated nitriles, thereby mimicking the intermediate Opsin-derived, protonated Schiff base in the visual cycle with simple polarized alkenes. Replacement of the iminium motif by a cyano group is well tolerated and gives an additional degree of versatility for postisomerization functionalization. Broad substrate scope is demonstrated (up to 99:1 Z:E) together with evidence of mechanistic dichotomy via both singlet and triplet energy transfer mechanisms. Kinetic studies, temperature dependent photostationary state correlations and investigation of substituent-based electronic perturbation of the alkene identified polarization combined with increased Z-isomer activation barriers as the selectivity governing factors in catalysis. This investigation demonstrates the importance of internal structural preorganization on photostationary composition and explicates the augmented Z-selectivity upon hydrogen-alkyl exchange at the β-position of the alkene.

Synthesis of carbo- and heterocycles via palladium catalysed cascade allene insertion-nucleophile incorporation-Michael addition processes

Novel palladium catalysed two- and three-component thermal (conventional heating and microwave) cascade processes are described involving allenylation of an aryl iodide to generate a (π-allyl)palladium species, which are intercepted (inter- or intramolecularly) by a carbon or nitrogen nucleophile followed by intramolecular Michael addition to afford carbo- and heterocycles in good yields.