Diastereo- and Enantioselective Pd(II)-Catalyzed Additions of 2-Alkylazaarenes to N-Boc Imines and Nitroalkenes
摘要:
A chiral Pd(II)-bis(oxazoline) complex was found to be highly effective in promoting the first direct diastereo- and enantioselective addition of alkylazaarenes to N-Boc aldimines and nitroalkenes under mild conditions. Deprotection of Boc-protected products proceeded readily to provide amines in high yields.
作者:Samuel D. Griggs、Nathan Thompson、Daniel T. Tape、Marie Fabre、Paul A. Clarke
DOI:10.1002/chem.201702467
日期:2017.7.12
A general two-stepsynthesis of 2-spiropiperidines has been developed. δ-Amino-β-ketoesters can be reacted with cyclic ketones to generate 2-spiropiperidines in good to excellent yields. The 2-spiropiperidines formed occupy an under-explored region of 3D-chemical space and are novel scaffolds for use in drug discovery programs. These 2-spiropiperidines can be further functionalised to generate small
Synthesis of highly substituted 2-spiropiperidines
作者:Samuel D. Griggs、Nathan Thompson、Daniel T. Tape、Marie Fabre、Paul A. Clarke
DOI:10.1039/c8ob01272e
日期:——
2-Spiropiperidines are a highly desirable, yet under represented structure in drug discovery. 2-Spiropiperidines were synthesised in either a two-pot or one-pot reaction. In the two-pot reaction, the addition of a Weiler dianion to N-Boc imines, followed by deprotection and in situ condensation with a cyclic ketone generated functionalised 2-spiropiperidines in good to excellent yields. In the one-pot
Direct Synthesis of Highly Substituted Pyrroles and Dihydropyrroles Using Linear Selective Hydroacylation Reactions
作者:Manjeet K. Majhail、Paul M. Ylioja、Michael C. Willis
DOI:10.1002/chem.201600311
日期:2016.6.1
diphosphine ligands, such as (Cy2 P)2 NMe or bis(diphenylphosphino)methane (dppm), are effective at catalysing the union of aldehydes and propargylic amines to deliver the linear hydroacylation adducts in good yields and with high selectivities. In situ treatment of the hydroacylation adducts with p-TSA triggers a dehydrative cyclisation to provide the corresponding pyrroles. The use of allylic amines, in place
An organocatalytic asymmetric Mannich reaction for the synthesis of 3,3-disubstituted-3,4-dihydro-2-quinolones
作者:Soumendranath Mukhopadhyay、Subhas Chandra Pan
DOI:10.1039/c8ob01399c
日期:——
The first organocatalytic asymmetric Mannichreaction employing 3,4-dihydro-2-quinolones has been developed for the synthesis of biologically important 3,3-disubstituted-dihydro-2-quinolones. N-Boc imine precursor amidosulfones as well as pre-formed N-Boc imine were used for this purpose. Cyclohexyldiamine derived bifunctional amino-thiourea catalysts were employed to provide the products in high enantio-
An efficient enantioselective vinylogous Mannichreaction of N-Boc aminosulfones with noncyclic α,α-dicyanoolefins has been realized using an extraordinary bifunctional thiourea–ammonium salt phase transfer catalyst derived from quinine. A variety of N-Boc aminosulfones and α,α-dicyanoolefins were investigated, and the corresponding products were obtained in excellent yields (up to 99% yield) with
N -Boc氨基砜与非环状α,α-二氰基烯烃的高效对映选择性乙烯基类Mannich反应已使用衍生自奎宁的非常规双官能硫脲-铵盐相转移催化剂实现。研究了各种N -Boc氨基砜和α,α-二氰基烯烃,并以优异的收率(最高99%的收率)和优异的对映选择性(最高ee的98%)获得了相应的产物。所需产物可以容易地转化成有价值的氨基酮。