Day: October 13, 2022

Hato, Yoshio; Oonishi, Yoshihiro; Yamamoto, Yasunori; Nakajima, Kiyohiko; Sato, Yoshihiro published the artcile< Stereoselective Construction of Spiro-Fused Tricyclic Frameworks by Sequential Reaction of Enynes, Imines, and Diazoalkenes with Rh(I) and Rh(II) Catalysts>, Application of C44H40P2, the main research area is stereoselective spiro fused tricyclic compound; rhodium catalyst imine tethered enyne reaction diazoalkene.

Stereoselective construction of spiro-fused tricyclic compounds from enynes having a tethered imine with diazoalkenes was achieved by Rh(I)- and Rh(II)-catalyzed sequential reactions. This method consists of three reactions, i.e., Rh(I)-catalyzed cyclization of enynes with a tethered imine, Rh(II)-catalyzed cyclopropanation with diazoalkenes, and Cope rearrangement. Notably, the sequential reactions can be operated in one pot, in which Rh(I) and Rh(II) catalysts work in relay without any serious catalyst deactivation to afford the spirocycles in a stereoselective manner.

Journal of Organic Chemistry published new progress about Alkenynes Role: RCT (Reactant), RACT (Reactant or Reagent). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Application of C44H40P2.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Kusama, Tomoya; Hirata, Shuzo published the artcile< Thermo-reversible persistent phosphorescence modulation reveals the large contribution made by rigidity to the suppression of endothermic intermolecular triplet quenching>, COA of Formula: C44H40P2, the main research area is diphenylphosphino binaphthyl triplet energy phosphorescence; diffusion constant; nonradiative deactivation; persistent room-temperature phosphorescence; phase change; reorganization energy; triplet quenching.

The suppression of thermally driven triplet deactivation is crucial for efficient persistent room-temperature phosphorescence (pRTP). However, the mechanism by which triplet deactivation occurs in metal-free mol. solids at room temperature (RT) remains unclear. Herein, we report a large pRTP intensity change in a mol. guest that depended on the reversible amorphous-crystal phase change in the mol. host, and we confirm the large contribution made by the rigidity of the host in suppressing intermol. triplet quenching in the guest. (S)-(-)-2,2′-Bis(diphenylphosphino)-1,1′- binaphthyl ((S)-BINAP) was doped as a guest into a highly purified (S)- bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl ((S)-H8-BINAP) host. It was possible to reversibly form the amorphous and crystalline states of the solid by cooling to RT from various temperatures The RTP yield (Φp) originating from the (S)-BINAP was 6.7% in the crystalline state of the (S)-H8-BINAP host, whereas it decreased to 0.31% in the amorphous state. Arrhenius plots showing the rate of nonradiative deactivation from the lowest triplet excited state (T1) of the amorphous and crystalline solids indicated that the large difference in Φp between the crystalline and amorphous states was mostly due to the discrepancy in the magnitude of quenching of intermol. triplet energy transfer from the (S)-BINAP guest to the (S)-H8-BINAP host. Controlled analyses of the T1 energy of the guest and host, and of the reorganization energy of the intermol. triplet energy transfer from the guest to the host, confirmed that the large difference in intermol. triplet quenching was due to the discrepancy in the magnitude of the diffusion constant of the (S)-H8-BINAP host between its amorphous and crystalline states. Quantification of both the T1 energy and the diffusion constant of mols. used in solid materials is crucial for a meaningful discussion of the intermol. triplet deactivation of various metal-free solid materials.

Frontiers in Chemistry (Lausanne, Switzerland) published new progress about Crystallinity. 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, COA of Formula: C44H40P2.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Williams, David R.; Shah, Akshay A. published the artcile< Total Synthesis of (+)-Ileabethoxazole via an Iron-Mediated Pauson-Khand [2 + 2 + 1] Carbocyclization>, Recommanded Product: (S)-(-)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is ileabethoxazole total synthesis Pauson Khand carbocyclization iron; Stille cross coupling total synthesis ileabethoxazole; insertion total synthesis ileabethoxazole; asym hydride reduction copper total synthesis ileabethoxazole.

Studies describe the total synthesis of (+)-ileabethoxazole (I) using a Stille cross-coupling reaction of propargylic stannanes with 5-iodo-1,3-oxazoles to produce 1,1-disubstituted allenes. An iron-mediated [2+2+1] carbocyclization yields a novel cyclopentenone II (R = H, Me) for elaboration to I. Site-selective palladium insertion reactions allow for regiocontrolled substitutions of the heterocycle. Asym. copper hydride reductions are examined, and strategies for the formation of the central aromatic ring are discussed.

Journal of the American Chemical Society published new progress about Cyclization (Pauson-Khand [2+2+1]-carbocyclization). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Recommanded Product: (S)-(-)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Bandini, Marco; Gualandi, Andrea; Monari, Magda; Romaniello, Alessandro; Savoia, Diego; Tragni, Michele published the artcile< Allylic alcohols: Valuable synthetic equivalents of non-activated alkenes in gold-catalyzed enantioselective alkylation of indoles>, Reference of 325168-88-5, the main research area is allylic alc tethered indole derivative preparation; chiral ligand gold catalyzed intramol allylic alkylation indole derivative; tetrahydrocarbazole derivative stereoselective preparation; tetrahydrocarboline derivative stereoselective preparation.

The recent booming of gold catalysis has demonstrated that unprecedented transformations can be realized in a highly selective manner. Moreover, due to the growing availability of chiral organic ligands, gold-catalysis can be considered as one of most dynamic hot spots in asym. synthesis. However, in this context, the use of non-activated olefinic C-C double bonds is still largely unexplored due to the intrinsic inertness of C=C (respect to allenes and alkynes) in taking part in nucleophilic additions assisted by π-electrophilic activations. Allylic alcs. have been demonstrated to be feasible “”surrogates”” of non-activated alkenes for the enantioselective allylic alkylation of indoles catalyzed by chiral gold(I) complexes. In this investigation, a full account addressing efficiency and substrate scope of such a process is presented. The products, tetrahydrocarbazoles or tetrahydro-β-carbolines, are obtained in moderate to good yields and 40-86% ee from the corresponding Z-allylic alc.-containing substrates, while the E isomers are unreactive.

Journal of Organometallic Chemistry published new progress about Allylic alcohols Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Reference of 325168-88-5.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Tanaka, Ken; Sagae, Hiromi; Toyoda, Kazuki; Noguchi, Keiichi; Hirano, Masao published the artcile< Enantioselective Synthesis of Planar-Chiral Metacyclophanes through Rhodium-Catalyzed Alkyne Cyclotrimerization>, Safety of (R)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is metacyclophane asym synthesis; alkyne stereoselective cyclotrimerization rhodium catalyst.

The first catalytic enantioselective synthesis of planar-chiral metacyclophanes via cationic rhodium(I)/(R)-H8-BINAP complex-catalyzed alkyne cyclotrimerization is described. This reaction represents a versatile new method for the preparation of planar-chiral [7]-[10]metacyclophanes.

Journal of the American Chemical Society published new progress about Alkadiynes Role: RCT (Reactant), RACT (Reactant or Reagent). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Safety of (R)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Trost, Barry M.; Xu, Jiayi; Schmidt, Thomas published the artcile< Ligand controlled highly regio- and enantioselective synthesis of α-acyloxyketones by palladium-catalyzed allylic alkylation of 1,2-enediol carbonates. [Erratum to document cited in CA149:307451]>, Related Products of 152140-65-3, the main research area is erratum enediol carbonate allyl alkylation palladium catalysis ligand; acetoxyketone asym preparation erratum.

On page 11853, in Table 2, entries 11 and 12, the stereochem. assignments of the cyclohexenyl ring of compound 20 and the cycloheptenyl ring of compound 22 should be S, not R. This assignment is based on the empirical model we proposed (Trost,B.M.; Toste, F.D. J. Am. Chem.Soc. 1999, 121,4545), which has been supported by extensive exptl. data.

Journal of the American Chemical Society published new progress about Alkyl aryl ketones Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 152140-65-3 belongs to class chiral-phosphine-ligands, and the molecular formula is C54H42N2O2P2, Related Products of 152140-65-3.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate