139372-13-7

Upstream product

• 201230-82-2 carbon monoxide 
• 766-77-8 Dimethylphenylsilane 
• 16079-17-7 N-(1,1-dimethyl-prop-2-ynyl)-4-methyl-benzenesulfonamide 
• 98-59-9 p-toluenesulfonyl chloride 
• 2978-58-7 1,1-dimethylprop-3-ynylamine 

Relevant academic research and scientific papers

Metal vapour derived supported rhodium nanoparticles in the synthesis of β-lactams and β-lactones derivatives

Functionalised β-lactones and β-lactams were prepared starting from propargyl alcohols and propargyl tosyl amides by means of efficient silylcarbocyclisation reactions catalysed by rhodium nanoparticles derived from mesitylene-solvated Rh atoms (Metal Vapour Synthesis technique, MVS) and deposited on inorganic (C, γ-Al2O3 Fe 2O3) and organic matrices (PBI). All the MVS supported nanoclusters resulted more active than the analogous commercial Rh/C and Rh/γ-Al2O3, as well as homogeneous Rh 4(CO)12 used as reference catalyst. In particular, metal vapour derived Rh/C afforded the β-lactones and β-lactams in high yields and chemoselectivity. Preliminary investigations on the nature of the real active metal species involved in the catalytic process showed that rhodium(0) naked nanoparticles are leached by the support. The high catalytic activity encountered with Rh/C could be ascribed to the easy leaching of metal nanoparticles from carbon into solution. Indeed, the presence of a more polar matrix determined a minor catalytic efficiency probably due to a stronger interaction between the metal and the support. Therefore MVS Rh/C species represents a source, stable with ageing at room temperature, of highly active metal nanoparticles.

Silylation-desilylation of propargyl amides: rapid synthesis of functionalised aldehydes and β-lactams

Propargyl functionalised β-silylalkenals were easily prepared starting from suitable propargyl compounds by a silylformylation process. In particular the use of propargyl tosyl amides allowed the synthesis of α,β-unsaturated aldehydes through a two-step sequence of silylformylation-desilylation reactions. TBAF was employed to induce the desilylation process that was performed under very mild experimental conditions and occurred along with an elimination step of the tosylamido moiety affording 2-methylaryl-2-alkenals with good yields and stereoselectivity. When the tosyl amides were reacted with a hydrosilane in the presence of catalytic amounts of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) α-silylmethylene-β-lactams were synthesised through a silylcarbocyclisation process. A high chemoselectivity towards the β-lactam was observed when dialkyl propargyl amides were employed. The obtained β-lactams were easily transformed into the corresponding methylaryl-β-lactams by fluoride induced aryl migration-desilylation with total retention of configuration of the migrating group and complete stereoselectivity towards the more stable β-lactam (E)-isomer.

A Novel Approach to α-Silylmethylene-β-lactams via Rh-catalyzed Silylcarbonylation of Propargylamine Derivatives

α-Silylmethylene-β-lactams are successfully constructed by the one-pot coupling of a substituted propargylamine derivative, a triorganosilane, and CO with the catalysis of Rh4(CO)12 and DBU.