Copper‐Catalyzed Oxidative C(<i>sp</i><sup>3</sup>)−H/N−H Cross‐Coupling of Hydrocarbons with P(O)−NH Compounds: the Accelerating Effect Induced by Carboxylic Acid Coproduct
An chelation‐assisted oxidative C(sp3)−H/N−H cross coupling of hydrocarbons with P(O)−NH compounds using copper acetate as catalyst is described. The results of kinetic experiments, mechanistic studies and DFT calculations demonstrate the importance of acetic acid coproduct as an additive for promoting the formation of intermediate bis((diphenylphosphoryl)(quinolin‐8‐yl)amino)copper (6), and consequently
Synthesis of<i>P</i>-Stereogenic Phosphinamides via Pd(II)-Catalyzed Enantioselective C–H Alkynylation
作者:Tao Zhou、Ling-Jie Fan、Zi-Jia Chen、Meng-Xue Jiang、Pu-Fan Qian、Xinquan Hu、Kun Zhang、Bing-Feng Shi
DOI:10.1021/acs.orglett.3c01865
日期:2023.8.11
compounds. Herein, we report Pd(II)-catalyzed enantioselective C–H alkynylation using cheap commercially available l-pyroglutamic acid as a chiral ligand. A range of structurally diverse P-stereogenic phosphinamides was prepared in good yields with high enantioselectivities via desymmetrization and kinetic resolution. A tailor-made congested directing group, N-ethyl-N-(3-methylpyridin-2-yl)amino, was
Process for preparing enamine derivatives, compounds so produced and process for preparing a 3-hydroxy-cephalosporin
申请人:Lilly Industries Limited
公开号:EP0019401A1
公开(公告)日:1980-11-26
There is described a process for preparing an enamine of formula (IX):
where R2 is a carboxylic acid protecting group and R3 is the residue of a carboxylic acid derived acyl group and where R5 and R6 are the same or different C1-4 alkyl or C7-10 aralkyl groups; or taken together with the adjacent nitrogen atom form a heterocyclic ring containing from 4 to 8 carbon atoms and optionally a further heteroatom selected from oxygen and nitrogen; by reacting a compound of formula (XII) :
with an amine of formula HNR5R6, the reactant of formula (XII) being prepared by reaction of an appropriate enol derivative with a phosphorus reagent. The enamines of formula (IX) are useful in the preparation of 3-hydroxycephalosporins.