Palladium(0)-Catalyzed Highly Regio- and Stereoselective Addition of Organoboronic Acids with 1,2-Allenylphosphonates Forming Tri- or Tetrasubstituted 1(<i>E</i>)-Alkenylphosphonates
作者:Shengming Ma、Hao Guo、Fei Yu
DOI:10.1021/jo060672t
日期:2006.8.1
A highly regio- and stereoselective palladium(0)-catalyzed addition of organoboronicacids with 1,2-allenylphosphonates in the presence of HOAc forming tri- or tetrasubstituted 1(E)-alkenylphosphonates is reported in this paper. The stereoselectivity is much higher than the reported cases. The effects of different R1, R2, and R3 were studied. A mechanism of this reaction is proposed on the basis of
Palladium(II)-Catalyzed Regio- and Stereoselective Hydroarylation of Diphenylphosphorylallenes with Arylboronic Acids in the Presence of Sodium Hydroxide and Oxygen
The palladium(II)‐catalyzed hydroarylation of diphenylphosphorylallenes (via 1,2‐addition of the allenic double bond) with arylboronicacids in the presence of sodium hydroxide and oxygen is developed. The regioselectivities turn out to be well controlled, affording 2‐aryl‐3‐(diphenylphosphinyl)alkenes as the only product. Moreover, the stereoselectivities for reactions of γ‐substituted allenes can
Rhodium-Catalyzed Highly Regioselective Hydroformylation-Hydrogenation of 1,2-Allenyl-Phosphine Oxides and -Phosphonates
作者:Hao Guo、Shengming Ma
DOI:10.1002/adsc.200800087
日期:2008.6.9
The rhodium-catalyzedhydroformylation-hydrogenation of 1,2-allenyl-phosphineoxides and -phosphonates is reported in this paper. The regioselectivity was well controlled, affording only saturated linear γ-phosphinyl aldehydes under the standard conditions: (carbonyl)tris(triphenylphosphine)-rhodium hydride [RhH(CO)(PPh3)3] (3 mol%), triphenylphosphine (PPh3) (10 mol%), carbon monoxide (CO) (2.4×106 Pa)
Synthesis of chiral phosphorus compounds from readily available substrates by a facile method is an attractive strategy. In this study, an efficient route for copper-catalyzedasymmetric boroprotonation of phosphinylallenes with bis(pinacolato)diboron with high regioselectivity was developed, affording chiral allylphosphine oxides in high yields with high enantioselectivities of up to 98% ee. The synthetic
通过简便的方法从容易获得的底物合成手性磷化合物是一种有吸引力的策略。在这项研究中,开发了一种铜催化的膦基丙二烯与双(频哪醇)二硼的高区域选择性不对称硼质子化的有效途径,以高产率和高达 98% ee 的高对映选择性提供手性烯丙基氧化膦。通过将手性烯丙基氧化膦轻松转化为几种立体特异性产物,进一步证明了合成效用。
Modular Synthesis of Tetrasubstituted Pyrroles via an Annulative Migration Reaction of Allenyl Ketones and <i>p</i>-Toluenesulfonylmethyl Isocyanide
The metal-free cyclization of allenylketones and p-toluenesulfonylmethyl isocyanide (TosMIC), promoted by Cs2CO3, provides a convenient access to tetrasubstituted pyrroles in which an acyl group undergoes 1,2-migration. This tandem Michael addition/annulative migration synthetic strategy is general and high-yielding for various substituted allenylketones. Moreover, a phosphoryl or ester moiety is
由 Cs 2 CO 3促进的联烯基酮和对甲苯磺酰甲基异氰化物 (TosMIC)的无金属环化提供了获得四取代吡咯的便捷途径,其中酰基经历 1,2-迁移。这种串联迈克尔加成/环状迁移合成策略对各种取代的丙二烯酮具有通用性和高产率。此外,磷酰基或酯部分也是使这种迁移成为可能的合适功能。