Synthesis of 1,3-Aminoalcohols and Spirocyclic Azetidines via Tandem Hydroxymethylation and Aminomethylation Reaction of β-Keto Phosphonates with <i>N</i>-Nosyl-<i>O</i>-(2-bromoethyl)hydroxylamine
作者:Binyu Wu、Hongbing Chen、Min Gao、Xiangnan Gong、Lin Hu
DOI:10.1021/acs.orglett.1c01091
日期:2021.6.4
α-aminomethylation reaction of aromatic cyclic β-keto phosphonates with N-nosyl-O-(2-bromoethyl)hydroxylamine in the presence of DBU base has been developed, affording a range of 1,3-aminoalcohols in good yields. The resultant products could be flexibly transformed into the spirocyclic and bispirocyclic azetidines via one step of Mitsunobu reaction. Mechanistic study revealed that hydroxylamine in situ generated
Hydrophosphonylation of Alkynes with Trialkyl Phosphites Catalyzed by Nickel
作者:Rosa E. Islas、Juventino J. García
DOI:10.1002/cctc.201700974
日期:2017.11.9
The use of simple and inexpensive NiCl2⋅6 H2O as a catalyst precursor for C−P bond formation in the presence of commercially available trialkyl phosphites (P(OR)3, R=Et, iPr, Bu, SiMe3) along with several alkynes is presented. Control experiments showed the in situ formation of (RO)2P(O)H as the species that undergo the addition into the C≡C bond at the alkynes to yield the product of P−H addition
利用简单且廉价的NiCl的2 ⋅6ħ 2在市售的三烷基亚磷酸酯的存在O作为催化剂前体对C-P键的形成(P(OR)3,R =的Et,我镨,卜,森达3)以及几种炔烃。对照实验表明,原位形成(RO)2 P(O)H,是在炔烃中经过CROC键加成后生成PH加成物的物种。二苯乙炔与P(OEt)3,P(O i Pr)3和P(OSiMe 3)3的氢膦酰基化无需特定的溶剂或配体,即可以高收率(> 92%)进行合成。该方法可用于制备作为末端炔烃模型的苯乙炔和内部炔烃的有机膦酸酯,其收率范围从良好到中等。
Asymmetric Synthesis of Tertiary α-Hydroxy Phosphonic Acid Derivatives under Aerobic Oxidation Conditions
作者:Biplab Maji、Hisashi Yamamoto
DOI:10.1055/s-0034-1380290
日期:——
The copper-catalyzed asymmetric α-hydroxylation of β-ketophosphonates, using in situ generated nitrosocarbonyl compounds as electrophilic source of oxygen, is reported. The reaction mergesaerobicoxidation and Lewis acid catalysis. α-Aminoxy-β-ketophosphonates were synthesized in high yields (up to 97% yield) and high enantioselectivities (up to >99% ee).
Platinum/Copper Dual‐Catalyzed Asymmetric Vinylogous Addition Reactions for the Synthesis of Functionalized Indoles
作者:Qingdong Hu、Chang Guo
DOI:10.1002/anie.202305638
日期:2023.7.24
An efficient platinum/copper dual-catalyzed asymmetric vinylogous addition reaction has been developed. This efficient process provides a novel approach for the asymmetricsynthesis of highly valuable indoles bearing a quaternary stereocenter with excellent enantioselectivity (up to 99 % ee).