46410-70-2

Upstream product

• 1372104-66-9 1-bromo-2-(2-vinylphenoxy)benzene 
• 1020959-71-0 2-(2-bromophenoxy)benzaldehyde 
• 95-56-7 2-hydroxybromobenzene 
• 446-52-6 2-Fluorobenzaldehyde 
• 108-95-2 phenol 
• 19434-34-5 2-(phenoxy)benzaldehyde 
• 2065-66-9 methyl-triphenylphosphonium iodide 

Downstream Products

• 19434-34-5 2-(phenoxy)benzaldehyde 

Relevant academic research and scientific papers

Site-Selective Acceptorless Dehydrogenation of Aliphatics Enabled by Organophotoredox/Cobalt Dual Catalysis

The value of catalytic dehydrogenation of aliphatics (CDA) in organic synthesis has remained largely underexplored. Known homogeneous CDA systems often require the use of sacrificial hydrogen acceptors (or oxidants), precious metal catalysts, and harsh reaction conditions, thus limiting most existing methods to dehydrogenation of non- or low-functionalized alkanes. Here we describe a visible-light-driven, dual-catalyst system consisting of inexpensive organophotoredox and base-metal catalysts for room-temperature, acceptorless-CDA (Al-CDA). Initiated by photoexited 2-chloroanthraquinone, the process involves H atom transfer (HAT) of aliphatics to form alkyl radicals, which then react with cobaloxime to produce olefins and H2. This operationally simple method enables direct dehydrogenation of readily available chemical feedstocks to diversely functionalized olefins. For example, we demonstrate, for the first time, the oxidant-free desaturation of thioethers and amides to alkenyl sulfides and enamides, respectively. Moreover, the system's exceptional site selectivity and functional group tolerance are illustrated by late-stage dehydrogenation and synthesis of 14 biologically relevant molecules and pharmaceutical ingredients. Mechanistic studies have revealed a dual HAT process and provided insights into the origin of reactivity and site selectivity.

RUTHENIUM-BASED METATHESIS CATALYSTS, PRECURSORS FOR THEIR PREPARATION AND THEIR USE

The invention is directed to ruthenium-based metathesis catalysts of the Grubbs-Hoveyda type. The new 2-aryloxy-substituted ruthenium catalysts described herein reveal rapid initiation behavior. Further, the corresponding styrene-based precursor compounds are disclosed. The catalysts are prepared in a cross-metathesis reaction starting from styrene-based precursors which can be prepared in a cost- effective manner. The new Grubbs-Hoveyda type catalysts are suitable to catalyze ring- closing metathesis (RCM), cross metathesis (CM) and ring- opening metathesis polymerization (ROMP). Low catalyst loadings are necessary to convert a wide range of substrates including more complex and critical substrates via metathesis reactions at low to moderate temperatures in high yields within short reaction times.

Ruthenium-based metathesis catalysts, precursors for their preparation and their use

The invention is directed to ruthenium-based metathesis catalysts of the Grubbs-Hoveyda type. The new 2-aryloxy-substituted ruthenium catalysts described herein reveal rapid initiation behavior. Further, the corresponding styrene-based precursor compounds are disclosed. The catalysts are prepared in a cross-metathesis reaction starting from styrene-based precursors which can be prepared in a cost-effective manner. The new Grubbs-Hoveyda type catalysts are suitable to catalyze ring-closing metathesis (RCM), cross metathesis (CM) and ring-opening metathesis polymerization (ROMP). Low catalyst loadings are necessary to convert a wide range of substrates including more complex and critical substrates via metathesis reactions at low to moderate temperatures in high yields within short reaction times.

Fast olefin metathesis: Synthesis of 2-aryloxy-substituted Hoveyda-type complexes and application in ring-closing metathesis

Four 1-(4-R-phenoxy)-2-ethenylbenzenes (R=NMe2, H, Cl, NO 2) 4a, 4b, 4c and 4d were reacted with the ruthenium complexes [RuCl2(NHC)(3-phenylindenylidene)(py)] in the presence of a protic resin to result in the formation of the respective Hoveyda-type complexes 5a-d {NHC=SIMes [1,3-bis(2,4,6-trimethylphenylimidazolin)-2-ylidene]} and 6a-d {NHC=SIPr [1,3-bis(2,6-diisopropylphenylimidazolin)-2-ylidene]} in 66-84% yield. The lower steric bulk and the decreased donation of the diaryl ether oxygen atoms in complexes 5 and 6 led to rapidly initiating precatalysts. The Ru(II/III) redox potentials of complexes 6 were determined (6a-d: ΔE=0.89-1.08 V). In the crystal structure of 5b two independent molecules were observed in the unit cell, displaying Ru-O distances of 226.6(4) and 230.5(3) pm. The catalytic performance of complexes 5 and 6 in various ring-closing metathesis (RCM) reactions was studied. Catalyst loadings of between 15-200 ppm are sufficient for the formation of >90% yield of the respective cyclic products. Complex 6b catalyzes the formation of N-protected 2,5-dihydropyrroles with up to TON 64,000 and TOF 256,000 h-1, of the N-protected 1,2,3,6- tetrahydropyridines with up to TON 18,200 and TOF 73,000 h-1 and of the N-protected 2,3,6,7-tetrahydroazepines with up to TON 8,100 and TOF 32,000 h-1 with yields ranging between 77 and 96%.

Three-step synthesis of (thio)xanthene and dibenzothiepine/dibenzoxepine by an intramolecular Mizoroki-Heck reaction of diaryl (thio)ethers

We present a novel three-step protocol for preparing xanthene/thioxanthene and dibenzothiepine/dibenzoxepine from readily available starting materials. The Mizoroki-Heck cyclization as the final step was optimized to afford full conversion of the corresponding diaryl (thio)ethers and furthermore to achieve reasonably good selectivity between the 6-exo and the 7-endo products. Georg Thieme Verlag Stuttgart · New York.