Direct conversion of secondary propargyl alcohols into 1,3-di-arylpropanone via DBU promoted redox isomerization and palladium assisted chemoselective hydrogenation in a single pot operation

Abstract

Palladium(II)acetate is found to be an efficient catalyst for the single-step conversion of secondary propargyl alcohol to 1,3-diarylpropanone derivatives under mild basic conditions. The reaction is believed to proceed via...

Palladium Catalyzed Selective 1,4‐Dihydrosilylation of Alkynones

“…(Table 1, entries 10-15) Next, solvents including DMC, THF, DMF, and NMP were evaluated, and DMF afforded the product 2 a in 94 % GC-yield and 88 % isolated yield, that was selected as the best solvent for this 1,4-dihydrosilylation of alkynone. (Table 1, entries [16][17][18][19] With the lower temperature to 30 °C, the yield of product 2 a was also decreased to 64 %, but 90 % yield for 8 h. (Table 1, entries 20 and 21) We subsequently investigated the effect of various alkynones on the efficiency of this 1,4-dihydrosilylation (Scheme 2). Firstly, 3-aryl ring of alkynone bearing substituents at the para or meta position such as -Me, -nBu, -Cl, -F, -Br groups smoothly converted to the corresponding 1,3-diarylpropanones under optimized reaction conditions with good yields.…”

“…However, other 1,3-disubstituted propanones synthetic process such as chemoselective 1,4-reduction of alkynones is a more challenging transformation due to their double reduction steps that has been less reported. [15][16][17] Recently, Wen's group developed an efficient transfer hydrogenation of alkynones with CH 3 OH as a hydrogen donor under electrochemical conditions. [15] (Scheme 1, a) Bera reported a 1,3-diaryl propanone derivatives synthetic method from secondary propargyl alcohols under Pd(OAc) 2 /DBU/HCO 2 H catalytic system.…”

“…[15] (Scheme 1, a) Bera reported a 1,3-diaryl propanone derivatives synthetic method from secondary propargyl alcohols under Pd(OAc) 2 /DBU/HCO 2 H catalytic system. [16] (Scheme 1, b)…”

Ir-Catalyzed α-Alkylation of Ketones with Alcohols: One-Step Access to Donepezil

“…1-(4-Isopropylphenyl)-3-phenylpropan-1-one (5g) 40 Yield: 89.5 mg (71%); light yellow oil. 1 H NMR (400 MHz, CDCl 3 ):  = 7.90 (d, J = 7.9 Hz, 2 H), 7.34-7.23 (m, 6 H), 7.21 (d, J = 7.8 Hz, 1 H), 3.28 (t, J = 7.7 Hz, 2 H), 3.06 (t, J = 7.7 Hz, 2 H), 2.96 (p, J = 6.8 Hz, 1 H), 1.26 (d, J = 6.8 Hz, 6 H).…”

A practical and cost-effective approach to polysubstituted pyrimidine derivativesviaDBU mediated redox isomerization of propargyl alcohol and subsequent N–C–N fragment condensation

“…Therefore, a straightforward approach towards pyrimidine derivatives under mild conditions and using commercially inexpensive substrates and reagents is highly desirable. As a part of our continuing interest in the chemistry of propargyl alcohol 26 and the synthesis of important heterocyclic compounds, 27 herein we report the direct conversion of secondary propargyl alcohol into poly-substituted pyrimidine derivatives under mild basic conditions. A large array of trisubstituted pyrimidine derivatives may be prepared from milligram to multigram scale under metal-free conditions.…”