39857-50-6

Upstream product

• 928-49-4 hex-3-yne 
• 97-94-9 triethyl borane 
• 64245-21-2 (E)-1-iodo-2-phenyl-1-butene 
• 925-90-6 ethylmagnesium bromide 
• 536-74-3 phenylacetylene 
• 3262-89-3 triphenylboroxine 
• 591-50-4 iodobenzene 
• 29443-43-4 propionaldehyde hydrazone 
• 93-55-0 1-phenyl-propan-1-one 
• 143-66-8 sodium tetraphenyl borate 
• 98-80-6 phenylboronic acid 

Relevant academic research and scientific papers

Recyclable and reusable PdCl2(PPh3)2/PEG-400/H2O system for the hydrophenylation of alkynes with sodium tetraphenylborate

A stable and efficient PdCl2(PPh3)2/PEG-400/H2O catalytic system for the hydrophenylation reaction of alkynes has been developed. In the presence of 3 mol% PdCl2(PPh3)2 and 2 equiv. of HOAc, the hydrophenylation of both terminal and internal alkynes with sodium tetraphenylborate proceeded smoothly in a mixture of PEG-400 and water at room temperature or 50 °C to afford a variety of phenyl-substituted alkenes in moderate to high yields. The isolation of the products was easily performed by extraction with petroleum ether, and the PdCl2(PPh3)2/PEG-400/H2O system could be readily recycled and reused six times without apparent loss of catalytic activity.

Allenoates in Enantioselective [2+2] Cycloadditions: From a Mechanistic Curiosity to a Stereospecific Transformation

Identification of a novel catalyst-allenoate pair allows enantioselective [2+2] cycloaddition of α-methylstyrene. To understand the origin of selectivity, a detailed mechanistic investigation was conducted. Herein, two competing reaction pathways are proposed, which operate simultaneously and funnel the alkenes to the same axially chiral cyclobutanes. In agreement with the Woodward-Hoffmann rules, this mechanistic curiosity can be rationalized through a unique symmetry operation that was elucidated by deuteration experiments. In the case of 1,1-diarylalkenes, distal communication between the catalyst and alkene is achieved through subtle alteration of electronic properties and conformation. In this context, a Hammett study lends further credibility to a concerted mechanism. Thus, extended scope exploration, including β-substitution on the alkene to generate two adjacent stereocenters within the cyclobutane ring, is achieved in a highly stereospecific and enantioselective fashion (33 examples, up to >99:1 er).

Ruthenium(II)-catalyzed olefination: Via carbonyl reductive cross-coupling

Natural availability of carbonyl groups offers reductive carbonyl coupling tremendous synthetic potential for efficient olefin synthesis, yet the catalytic carbonyl cross-coupling remains largely elusive. We report herein such a reaction, mediated by hydrazine under ruthenium(ii) catalysis. This method enables facile and selective cross-couplings of two unsymmetrical carbonyl compounds in either an intermolecular or intramolecular fashion. Moreover, this chemistry accommodates a variety of substrates, proceeds under mild reaction conditions with good functional group tolerance, and generates stoichiometric benign byproducts. Importantly, the coexistence of KOtBu and bidentate phosphine dmpe is vital to this transformation.

Palladium-catalyzed hydrophenylation of alkynes with sodium tetraphenylborate under mild conditions

(Chemical Equation Presented) In an aqueous solution of acetic acid, PdCl2(PPh3)2 showed high catalytic activity for the hydrophenylation of both terminal and internal alkynes with sodium tetraphenylborate (NaBPh4) under mild conditions, affording phenyl alkenes in moderate to excellent yields.