CuI‐Catalyzed Synthesis of Functionalized Terminal Allenes from 1‐Alkynes

Abstract

Relative to our original protocol that uses CuI (0.5 equiv.), paraformaldehyde (2.5 equiv.), and dicyclohexylamine (1.8 equiv.), a facile and efficient protocol for the gram‐scale synthesis of functionalized terminal allenes by using CuI (7.5–10 mol‐%), paraformaldehyde (1.6 equiv.), and diisopropylamine (1.4 equiv.) has been developed. This method accommodates different functional groups such as hydroxy or carbonyl, and it also performed well in the synthesis of allenylamides and 2,3‐butadien‐1‐ol.

Enhanced Detection of Nitrite Ions Over Copper Acetylacetonate/Polymeric Carbon Nitride Composites

“…As shown in Figure 1, the polymeric CN showed vibration bands at around 3300-3400 cm À1 due to the overlapping bands from the secondary and primary amines and incomplete graphitic condensation and v(O-H) group. [21] The stretching mode of the v (C-N) heterocycles originated from the extended CN network were observed at 1200-1700 cm À1 , [3] while the vibration bands at 809 cm À1 was corresponded to the heterocyclic tri-s-triazine ring (C 6 N 7 ) units with single and double bonds, which showed the characteristics of the graphitic polymeric CN. [22,23] The presence of these peaks confirmed the successful formation of the polymeric CN.…”

“…[1] The polymeric CN is categorized as a semiconductor with band gap energy of $ 2.7 eV [2] and it contains graphitic stacking of CN layers, which are constructed from tri-s-triazine units connected by planar amino groups. [3] It can be produced on a large scale with low cost by bulk condensation of N-rich precursors, including urea, cyanamide and melamine. [1] The polymeric CN has been reported to show high photoluminescence (PL) intensity, good photostability, and excellent biocompatibility.…”

Cu‐Catalyzed Aerobic Oxidative Cyclizations of 3‐N‐Hydroxyamino‐1,2‐propadienes with Alcohols, Thiols, and Amines To Form α‐O‐, S‐, and N‐Substituted 4‐Methylquinoline Derivatives

“…Equation (4) shows a synthetic protocol for the starting N ‐hydroxyaminoallenes 1 ; 2,3‐butadienols10a, b were first transformed into their acetyl derivatives, which were subsequently treated with [Pd(PPh 3 ) 4 ] (4 mol %) and a N ‐hydroxyaniline species (1 equiv) 10c. Table 1 shows the aerobic oxidation of N ‐hydroxy aminoallene 1 a with various copper catalysts and oxidants.…”

Cadmium iodide-mediated allenylation of terminal alkynes with ketones

“…Thus, efficient methods for the synthesis of allenes from simple and readily available chemicals are highly desirable [26][27][28][29][30][31][32][33][34][35][36] . For such a reaction, the most straight forward method is using the allenylation of terminal alkynes (ATA) reaction due to the fact that all the starting materials, that is, terminal alkynes, amines, carbonyl compounds (aldehydes and ketones), are common chemicals in any chemical laboratory [37][38][39][40][41] . However, so far this ATA reaction may only be applied to paraformaldehyde (with Cu I ) [37][38][39][40] and aldehydes (with Zn II or Cu(I)) 41 for the synthesis of mono-and 1,3-disubstituted allenes.…”

“…For such a reaction, the most straight forward method is using the allenylation of terminal alkynes (ATA) reaction due to the fact that all the starting materials, that is, terminal alkynes, amines, carbonyl compounds (aldehydes and ketones), are common chemicals in any chemical laboratory [37][38][39][40][41] . However, so far this ATA reaction may only be applied to paraformaldehyde (with Cu I ) [37][38][39][40] and aldehydes (with Zn II or Cu(I)) 41 for the synthesis of mono-and 1,3-disubstituted allenes. The synthesis of trisubstituted allenes from this approach using ketones is still not possible (Fig.…”