铜(I)催化剂可通过使用合适的有机碱将二氧化碳插入炔烃的C H键中,利用该有机碱在热力学上可实现对羧酸盐的氢化以及碱的再生。在催化氯化铜(I)/ 4,7-二苯基-1,10-菲咯啉,聚合物结合的三苯基膦和2,2,6,6-四甲基哌啶为碱的情况下,末端炔烃在15 bar CO下进行羧化反应2,室温。过滤后,可以在铑/钼催化剂下将炔羧酸铵氢化为伯醇和水,以再生胺碱。这证明了无盐整体工艺的可行性,在该工艺中,二氧化碳可充当CH功能中C1的基石。
Direct Synthesis of 4-Quinolones via Copper-Catalyzed Anilines and Alkynes
作者:Xuefeng Xu、Xu Zhang
DOI:10.1021/acs.orglett.7b02495
日期:2017.9.15
and direct approach for constructing 4-quinolones from simple and readily available anilines and alkynes is described. Under the optimal conditions, both N-alkyl- and N-aryl-substituted anilines can be successfully transformed into the corresponding 4-quinolones. This reaction is characterized by mild reaction conditions, high functional-group tolerance, and amenability to gram-scale synthesis.
efficient asymmetric cascade reaction between alkynyl esters and allylic alcohols has been realized. Key to success was the combination of a hydroalkoxylation reaction catalyzed by a π‐acidic gold(I) complex with a Claisen rearrangement catalyzed by a chiral Lewis acidic N,N′‐dioxide–nickel(II) complex. A range of acyclic α‐allyl β‐keto esters were synthesized in high yields (up to 99 %) with good
Organocatalytic
<i>trans</i>
Phosphinoboration of Internal Alkynes
作者:Russell G. Fritzemeier、Jan Nekvinda、Christopher M. Vogels、Carol Ann Rosenblum、Carla Slebodnick、Stephen A. Westcott、Webster L. Santos
DOI:10.1002/anie.202006096
日期:2020.8.17
We report the first trans phosphinoboration of internal alkynes. With an organophosphine catalyst, alkynoate esters and the phosphinoboronate Ph2P‐Bpin are efficiently converted into the corresponding trans‐α‐phosphino‐β‐boryl acrylate products in moderate to good yield with high regio‐ and Z‐selectivity. This reaction operates under mild conditions and demonstrates good atom economy, requiring only
Rhodium(III)-Catalyzed Redox-Neutral Cascade [3 + 2] Annulation of <i>N</i>-Phenoxyacetamides with Propiolates via C–H Functionalization/Isomerization/Lactonization
A Rh(III)-catalyzed cascade [3 + 2] annulation of N-phenoxyacetamides with propiolates under mild conditions using the internal oxidative O–N bond as the directing group has been achieved. This catalytic system provides a regio- and stereoselective access to benzofuran-2(3H)-ones bearing exocyclic enamino motifs with exclusive Z configuration selectivity, acceptable to good yields and good functional
Transition Metal-Free <i>Trans</i> Hydroboration of Alkynoic Acid Derivatives: Experimental and Theoretical Studies
作者:Russell Fritzemeier、Ashley Gates、Xueying Guo、Zhenyang Lin、Webster L. Santos
DOI:10.1021/acs.joc.8b01493
日期:2018.9.7
(E)-β-boryl acrylamides in good to excellent yields. The reaction is tolerant of a variety of functional groups and allows efficient access to novel oxaboroles as well as a pargyline derivative (MAO inhibitor). Theoretical calculations suggest an internal hydride generates a phosphonium allenoxyborane followed by the formation of a key phosphonocyclobutene intermediate that collapses in a stereoselective