106175-44-4

Upstream product

• 94607-41-7 (E)-1-(4-methoxyphenyl)-3-chloropropene 
• 30043-41-5 (hex-5-enyl)magnesium bromide 
• 61691-82-5 1'-acetoxyestragole 
• 2564-83-2 2,2,6,6-tetramethyl-piperidine-N-oxyl 
• 507-19-7 t-butyl bromide 

Relevant academic research and scientific papers

Enantioselective Reductive Homocoupling of Allylic Acetates Enabled by Dual Photoredox/Palladium Catalysis: Access to C2-Symmetrical 1,5-Dienes

Transition-metal-catalyzed reductive coupling reactions have emerged as powerful protocols to construct C-C bonds. However, the development of enantioselective C(sp3)-C(sp3) reductive coupling remains challenging. Herein, we report a highly regio-, diastereo-, and enantioselective reductive homocoupling of allylic acetates through cooperative palladium and photoredox catalysis using diisopropylethylamine or Hantzsch ester as a homogeneous organic reductant. This straightforward protocol enables the stereoselective construction of C(sp3)-C(sp3) bonds under mild reaction conditions. A series of C2-symmetrical chiral 1,5-dienes were easily prepared with excellent enantioselectivities (up to >99% ee), diastereoselectivities (up to >95:5 dr), and regioselectivities (up to >95:5 rr). The resultant chiral 1,5-dienes can be directly used as chiral ligands in asymmetric synthesis, and they can be also transformed into other valuable chiral ligands.

Reaction of 1-Arylpropenyl-lithium with t-Alkyl Bromides. The Influence of Substituent Electronic Effects and Additives on the Course of the Reaction

The reaction of 1-arylpropenyl-lithium (1a-c) with t-alkyl bromides proceeds by either a nucleophilic substitution or single electron transfer mechanism, the preferred pathway being a function of electronic substituent effects and the absence or presence of tetramethylethylenediamine or hexamethylphosphoramide.

Reaction of 1-Aryl-3-chloropropenes with Grignard Reagents. Nucleophilic Substitution versus Single-electron Transfer

The reactions of ambident 1-aryl-3-chloropropenes (1a-e) with a series of Grignard reagents, R'MgY (R' = Me, Pr, Ph, Pri, But; Y = Br, I), were carried out in diethyl ether (EE) and tetrahydrofuran (THF).The products were a mixture of two alkylation products (2) and (3), and three dimerization products (4)-(6).The alkylation:dimerization ratio and the composition of the two alkylation products were a marked function of substituent electronic effects in the chlorides (1a-e), R' or Y of R'MgY, and solvent.On the basis of the stereochemistry of alkylation, cyclizable probe experiments, and the effect of the addition of FeCl3 on product composition, the following conclusions were obtained.First, dimers (4)-(6) are most likely to be produced by a mechanism involving single-electron transfer (SET).Second, for the formation of alkylation products (2) and (3), three alternative pathways contribute depending on the nature of R'MgY and solvent, (a) competitive SN2-SN2' pathways in the reaction of R'MgBr in EE, (b) a process involving SET in the reaction with R'MgI in EE, and (c) SN2 pathways in the reaction of R'MgBr in THF.