DABCO mediated one pot synthesis of sulfoxonium ylides under blue LED

Visible-Light-Mediated Strategies to Assemble Alkyl 2-Carboxylate-2,3,3-Trisubstituted β-Lactams and 5-Alkoxy-2,2,4-Trisubstituted Furan-3(2H)-ones Using Aryldiazoacetates and Aryldiazoketones

“…In this context, , we became interested in the blue-light-mediated photolysis of aryldiazoacetates 1 to afford carbenes 2 , which could sequentially react either with azides 3 or sulfoxides 5 to afford imines 4 or sulfoxonium ylides 6 , , respectively. Sequential reaction with diazoketones 7 , also under blue light irradiation, could then potentially convert imines 4 to β-lactams 9 (some members of this class of compounds have been previously accessed via metal catalysis) , and sulfoxonium ylides 6 to furan-3­(2H)-ones 10 by taking advantage of a ketene intermediate 8 generated from a photochemically promoted Wolff rearrangement (Scheme ).…”

Visible-light-induced organocatalytic enantioselective N–H insertion of α-diazoesters enabled by indirect free carbene capture

“…We hypothesized that the lone pair on sulfur, phosphorus, or halogen might be able to trap the free carbene, and the resulting ylides from these species could be both stable and reactive. 12 In particular, sulfur ylides have been used for asymmetric H–X bond insertion reactions. 14,15 Thus, we examined PPh 3 , halobenzenes and sulfides, but they did not lead to any obvious improvement.…”

“…We hypothesized that the enantioselectivity would be improved if the free carbene, once generated, could be immediately captured by an additive Y to in situ generate a less-reactive intermediary carbenoid species ( e.g. , ylide), 12 which would react with the amine in a more controlled manner ( Scheme 3 ). However, several requirements need to be fulfilled in this design.…”

Visible light-mediated photolysis of organic molecules: the case study of diazo compounds

“…69 Sulfoxonium ylides are versatile, isolable sulfur(VI) ylides, which can be also readily accessed from sulfoxides. 34,70,71 On the other hand, nitrogen ylides can be also generated in situ and sequentially engaged in sigmatropic rearrangements to afford homoallyl amines. 72 Oxygen ylides have been also explored as key intermediates in ring-expansion strategies employing strained oxetanes to produce substituted THFs, 73 while a ring-contraction method was applied to 2,5-dihydrofurans to afford 3-vinyl oxetanes.…”