Synthesis of 1,4-diketones by the reaction of lithium aroyltricarbonylnickelates with acetylenes

New Synthesis of Furans: the Rhodium‐Catalysed Carbonylative Addition of Arylboronic Acids to Propargylic Alcohols/ Cyclisation Sequence

“…A further improvement was reached after the use of an additional amount of lithium iodide in combination with this precursor. The combination of lithium iodide with the commercially available complex [Rh(CO) 2 Cl] 2 does not give the same improvement of yield. Although this effect cannot be easily rationalised, it is noteworthy that the use of an iodide ligand has led to important improvements in several catalytic reactions.…”

“…A screening was made using several rhodium precursors ( Table 2). The combination of a phosphorus- 2 is strongly limiting and in all cases led to lower yields (entries 1-5). The amount of 2-phenylfuran obtained was decreased with increasing phosphorus content in the reaction medium.…”

“…It turned out that the halogen has an important role in the course of the reaction. We thus focused our attention to an alternative to the chloride by using [Rh(CO) 2 I] 2 . This complex indeed led to significant improvements in the yield (Scheme 3).…”

“…Stoichiometric organometallic, unmasked acylation reagents were extensively developed and reacted with alkynes. [2] However, this strategy is limited by the large wastage of metal needed for the synthesis of the targeted ketones. Thus, it turns out that alternative reactions that would involve catalytic amounts of metal are needed for economic and environmental reasons.…”

Reaction of acetophenone and benzylphenylketone oximes with phenylacetylene: synthesis of di- and triphenylpyrroles

“…The diethyl ether was removed to afford 6.73 g of mixture containing 39% of 2,3,4-triphenyl-1Н-pyrrole (6), 30% of the oxime 2, 15% of 2,3,4-triphenyl-1-[(Z)-2-phenylethenyl]-1H-pyrrole (8), 14% of 2,3,5-triphenyl-1Н-pyrrole (7) and 2% of benzylphenylketone ( 1 Н NMR). The mixture obtained was dissolved in hot ethanol, the latter was cooled and the fine light-yellowish crystals precipitated were filtered off and dried to give 0.69 g (7%) of 2,3,4-triphenyl-1-[(Z)-2-phenylethenyl]-1H-pyrrole (8). Ethanol was removed from the filtrate and the residue was separated by preparative TLC (Al 2 O 3 , eluent -hexane : ethylacetate, 10:1) to obtain 1.21 g (17 %) of 2,3,4-triphenyl-(6) and 2,3,5-triphenyl-1H-pyrroles (7) mixture (ratio of 6 : 7 was 7 : 3, 1 Н NMR), 1.51 g of the starting oxime 2 (70% conversion).…”