203250-08-2

Upstream product

• 135006-32-5 4-tert-butyldiphenylsilyloxy-1-butene 
• 58479-61-1 tert-butylchlorodiphenylsilane 

Downstream Products

• 203250-25-3 4-(tert-Butyl-diphenyl-silanyloxy)-1-trityloxy-butan-2-ol 
• 203250-09-3 (3-Allyloxy-4-trityloxy-butoxy)-tert-butyl-diphenyl-silane 
• 203250-10-6 2-[3-(tert-Butyl-diphenyl-silanyloxy)-1-trityloxymethyl-propoxy]-ethanol 
• 203250-11-7 Methanesulfonic acid 2-[3-(tert-butyl-diphenyl-silanyloxy)-1-trityloxymethyl-propoxy]-ethyl ester 
• 203719-72-6 2-[1-(2-{3-(2,2-dimethyl-1,1-diphenyl-1-silapropoxy)-1-[(triphenylmethoxy)methyl]propoxy}ethyl)indol-3-yl]ethanamide 

Relevant academic research and scientific papers

Pt-catalyzed enantioselective diboration of terminal alkenes with B 2(pin)2

(Chemical Equation Presented) The Pt-catalyzed enantioselective addition of bis(pinacolato)diboron to simple monosubstituted alkenes is described. This reaction occurs in the presence of a readily available chiral phosphonite ligand and is effective with a variety of terminal alkene substrates. Importantly, the reaction can operate with catalyst loadings of only 1 mol % Pt. While oxidation of the intermediate 1,2-bis(boronate) ester provides the chiral 1,2-diol as the reaction product, the intermediate may also be subjected to homologation/oxidation to furnish a chiral 1,4-diol as the reaction product.

NOVEL PHARMACEUTICAL COMPRISING HETEROAROMATIC AMIDE DERIVATIVE OR SALT THEREOF

PROBLEM TO BE SOLVED: To provide a compound useful for treating or preventing disease associated with voltage-dependent sodium channel (Nav1.7) such as disease involving a pain, disease involving an itch, autonomic nerve-associated disease, or a pharmaceutical composition thereof. SOLUTION: The present disclosure provides a compound illustrated by the following formula, and a pharmaceutical composition containing the same. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT

Site-Selective Mono-Oxidation of 1,2-Bis(boronates)

Site-selective oxidation of vicinal bis(boronates) is accomplished through the use of trimethylamine N-oxide in 1-butanol solvent. The reaction occurs with good efficiency and selectivity across a range of substrates, providing 2-hydro-1-boronic esters which are shown to be versatile intermediates in the synthesis of chiral building blocks.

Aerobic Acetoxyhydroxylation of Alkenes Co-catalyzed by Organic Nitrite and Palladium

An aerobic acetoxyhydroxylation of alkenes cooperatively catalyzed by organic nitrite and palladium at room temperature using clean and cheap air as the sole oxidant has been developed. Various vicinal diols, diacetoxyalkanes, and dihalogenoalkanes have been synthesized. The gram-scale synthesis has also been approached. Vicinal difluorination and dichlorolation products have also been achieved via this reaction.

Scope and mechanism of the Pt-catalyzed enantioselective diboration of monosubstituted alkenes

The Pt-catalyzed enantioselective diboration of terminal alkenes can be accomplished in an enantioselective fashion in the presence of chiral phosphonite ligands. Optimal procedures and the substrate scope of this transformation are fully investigated. Reaction progress kinetic analysis and kinetic isotope effects suggest that the stereodefining step in the catalytic cycle is olefin migratory insertion into a Pt-B bond. Density functional theory analysis, combined with other experimental data, suggests that the insertion reaction positions platinum at the internal carbon of the substrate. A stereochemical model for this reaction is advanced that is in line both with these features and with the crystal structure of a Pt-ligand complex.

Silyl group deprotection by Pd/C/H2. A facile and selective method

An easy, high yield, RT, short-reaction-time Pd/C hydrogenation of silyl groups is described. This includes TES, TPS, TBS, TBDMS, TIPS, and TBDPS. The relative selectivity of the process has been investigated and we can show, for example, that TES, TPS, TBS, and TBDMS removal can be performed in the presence of TIPS and TBDPS.

Cyclization strategies for the synthesis of macrocyclic bisindolylmaleimides

Three new approaches to the synthesis of macrocyclic bisindolylmaleimides 1-4 have been identified. Two strategies afford 8, the penultimate intermediate for the synthesis of 1-4, in 73% and 32% yield by intramolecular cyclization of 31 and 40, respectively. The optimum synthesis of 1 was achieved in nine steps and 15% yield by intramolecular formation of the macrocycle and maleimide in one step by reaction of the sodium indolate of 12 with methyl indole-3-glyoxylate 47. The mechanism of this reaction has been elucidated, using the trityl-protected derivative, to involve initial formation of the tricarbonyl imide 48, followed by irreversible alkylation of the indole nitrogen to generate the 17-membered macrocycle 49. Cyclization of 49 to hydroxymaleimide 50 and subsequent dehydration afforded 8a. This approach eliminated the problem of dimerization observed in the intramolecular cyclization reactions.

Macrocyclic bisindolylmaleimides: Synthesis by inter- and intramolecular alkylation

Macrocyclic bisindolylmaleimides 1-4 have been identified as competitive reversible inhibitors of PKC β1 and β2 and are being advanced to the clinic for evaluation as a treatment of retinopathy associated with diabetic complications. Highly convergent and stereoselective syntheses of 1-4 have been developed. The key synthetic step involves intermolecular alkylation of symmetrical bisindolylmaleimide 9 with chiral bisalkylating agent 8c and is amenable to the preparation of multikilogram quantities of these compounds. The synthetic sequence to 1, the most active the compound, proceeds in 11 steps and 26% overall yield (> 98% ee) from (R)-1-chloro-2,3-propanediol. No chromatographic purifications are required throughout the process and the final product is isolated in >97% purity after crystallization from DMF/MeOH. Synthesis of 1-4 by intramolecular alkylation proved less efficient, requiring 17 steps and affording 1-4 in lower overall yields of 6.0-8.5%.