Electron Withdrawing Substituents on Equatorial and Apical Phosphines Have Opposite Effects on the Regioselectivity of Rhodium Catalyzed Hydroformylation
摘要:
The electronic effects of electron withdrawing aryl substituents on equatorial and apical diphosphines were investigated. Chelating diphosphines designed to coordinate in diequatorial or in apical-equatorial positions were synthesized, and their effects on the regioselectivity of rhodium catalyzed 1-hexene hydroformylation were observed. Only diequatorial coordination was observed for 2,2'-bis[(diphenylphosphino)methyl]-1,1'-biphenyl (BISBI) complexes (BISBI)Ir(CO)(2)H (8) and [BISBI-(3,5-CF3)]Ir(CO)(2)H (10), and only apical-equatorial coordination was seen for 1,2-bis(diphenylphosphino)ethane (DIPHOS) complexes (DIPHOS)Ir(CO)(2)H (14) and [DIPHOS-(3,5-CF3)]Ir(CO)(2)H (15). For the trans-1,2-bis [(diphenylphosphino)methyl] cyclopropane (T-BDCP) complexes, a mixture of diequatorial and apical-equatorial complexes was seen. For (T-BDCP)Ir(CO)(2)H (12), 12-ee was favored over 12-ee by 63:37, but for [T-BDCP-(3,5-CF3)]Ir(CO)(2)H (13) the conformational preference was reversed and a 10:90 ratio of 13-ee:13-ee was seen. The electron withdrawing groups in the equatorial positions of BISBI-(3,5-CF3) (1) and T-BDCP-(3,5-CF3) (2) led to an increase in n-aldehyde regioselectivity in rhodium catalyzed hydroformylation. However, electron withdrawing aryl substituents in the apical positions of DIPHOS-(3,5-CF3) (3) led to a decrease in n-aldehyde regioselectivity in rhodium catalyzed hydroformylation.
据报道,[Rh I ] /双膦/碱催化体系可通过丙烯酸酯和丙烯酰胺对嗪进行邻位选择性C H烷基化。该催化体系具有前所未有的完全线性或支化选择性,这完全取决于所使用的催化碱。甲基丙烯酸乙酯甚至可以实现完全支化的选择性,从而可以引入季碳中心。对于直链和支链烷基化都表现出优异的官能团相容性。这种转化的操作简便性和广泛范围使其可以快速获得具有直接制药和农用化学相关性的功能化杂志。
C2-Selective Branched Alkylation of Benzimidazoles by Rhodium(I)-Catalyzed C–H Activation
作者:Gaël Tran、Danielle Confair、Kevin D. Hesp、Vincent Mascitti、Jonathan A. Ellman
DOI:10.1021/acs.joc.7b01723
日期:2017.9.1
Herein, we report a Rh(I)/bisphosphine/K3PO4 catalytic system allowing for the first time the selective branched C–H alkylation of benzimidazoles with Michael acceptors. Branched alkylation with N,N-dimethyl acrylamide was successfully applied to the alkylation of a broad range of benzimidazoles incorporating a variety of N-substituents and with both electron-rich and -poor functionality displayed
在本文中,我们报道了Rh(I)/双膦/ K 3 PO 4催化体系,首次使苯并咪唑与Michael受体进行了选择性支链C–H烷基化。用N,N-二甲基丙烯酰胺进行的支化烷基化已成功地用于各种苯并咪唑的烷基化反应,这些苯并咪唑掺入了各种N-取代基,并且在芳烃的不同部位均显示出富电子和贫电子的功能。此外,通过用甲基丙烯酸乙酯进行烷基化来引入季碳。该方法还显示出可用于氮杂苯并咪唑的C 2-选择性支链烷基化。
Method for producing 1-menthol
申请人:——
公开号:US20020007094A1
公开(公告)日:2002-01-17
Provided is a method for the production of 1-menthol, which comprises hydrogenation of piperitenone with a transition metal complex of a specified optically active phosphine to produce pulegone, hydrogenation of the obtained pulegone with a ruthenium-phosphine-amine complex in the presence of base to obtain pulegol, and further hydrogenation of the pulegol with a transition metal catalyst.
Utilisation pour le décapage de la couleur artificielle des fibres kératiniques d'une composition comprenant au moins une phosphine à titre d'argent réducteur majoritaire
申请人:L'OREAL
公开号:EP1598053A1
公开(公告)日:2005-11-23
La présente invention a pour objet l'utilisation pour le décapage de la couleur artificielle des fibres kératiniques d'une composition comprenant au moins une phosphine ou l'un de ses sels d'addition avec un acide à titre d'agent réducteur majoritaire, le procédé de décapage de la couleur artificielle des fibres kératiniques mettant en oeuvre cette composition et un dispositif à plusieurs compartiments destiné à la teinture puis au décapage de la couleur artificielle des fibres kératiniques.
La présente invention fournit un produit de décapage de la couleur artificielle des fibres kératiniques teintes avec une large palette de colorants d'oxydation et / ou de colorants directs, qui n'induit pas d'éclaircissement de la base naturelle des fibres kératiniques, qui soit plus pratique d'utilisation et qui limite la sensibilisation des fibres kératiniques.
Polymerizable compositions comprising a radically polymerizable resin can be polymerized in the absence of a peroxide initiator and other undesirable components. The polymerizable compositions and methods employ a manganese- or iron-containing salt or organic complex and a 1,3-dioxo compound with one or more other components. The polymerizable compositions have better storage stability and reduced gel time-drift.