Annulation of Diaryl(aryl)phosphenes and Cyclic Imines to Access Benzo-δ-phospholactams
作者:Yun Luo、Jiaxi Xu
DOI:10.1021/acs.orglett.0c02346
日期:2020.10.16
Microwave-assisted annulation of cyclicimine dibenzo[b,f][1,4]oxazepines and diaryl(aryl)phosphenes generated from diazo(aryl)methyl(diaryl)phosphine oxides through the Wolff rearrangement accesses pentacyclic benzo-δ-phospholactams, 4b,16-dihydrodibenzo[b,f]benzo[4,5][1,2]azaphosphinino[1,6-d][1,4]oxazepine 15-oxides, in good yields.
The first organocatalytic asymmetric aza‐Henry reaction of unactivated seven‐membered cyclicimines, dibenzo[b,f][1,4]oxazepines, with nitroalkanes has been achieved. In the presence of 10 mol‐% quinine‐derived thiourea, a range of chiral 11‐(nitromethyl)‐10,11‐dihydrodibenzo[b,f][1,4]oxazepine derivatives were produced in good to excellent yields (up to 97 %) and enantioselectivities (up to 98 % ee)
Dibenzo[b,f][1,4]oxazepine derivatives were synthesized in good yields and short reaction times by the reaction of 2‐chlorobenzaldehydes and 2‐aminophenoles in basic conditions under microwave irradiation.
the preparation of a variety of biologically interesting amido (thio)xanthates has been developed. By the proper choice of a potassium (thio)xanthate salt, a cyclic or acyclic imine, and an acyl chloride as substrates a broad scope with respect to the substituents can be realized. This operationally simple one-pot method proceeds under mild and environmentally friendly conditions while potassium chloride
Direct Amine-Catalyzed Enantioselective Synthesis of Pentacyclic Dibenzo[<i>b</i>,<i>f</i>][1,4]oxazepine/Thiazepine-Fused Isoquinuclidines along with DFT Calculations
A direct protocol for the asymmetric synthesis of dibenzoxazepine/thiazepine-fused [2.2.2] isoquinuclidines is developed. The reaction proceeds through a proline-catalyzed direct Mannich reaction followed by an intramolecular aza-Michael cascade sequence between 2-cyclohexene-1-one and various tricyclic imines, like dibenzoxazepines/thiazepines, as an overall [4 + 2] aza-Diels–Alder reaction. A series