Rate Dependence on Inductive and Resonance Effects for the Organocatalyzed Enantioselective Conjugate Addition of Alkenyl and Alkynyl Boronic Acids to β-Indolyl Enones and β-Pyrrolyl Enones
作者:Amy Boylan、Thien S. Nguyen、Brian J. Lundy、Jian-Yuan Li、Ravikrishna Vallakati、Sasha Sundstrom、Jeremy A. May
DOI:10.3390/molecules26061615
日期:——
Two key factors bear on reaction rates for the conjugate addition of alkenylboronicacids to heteroaryl-appended enones: the proximity of inductively electron-withdrawing heteroatoms to the site of bond formation and the resonance contribution of available heteroatom lone pairs to stabilize the developing positive charge at the enone β-position. For the former, the closer the heteroatom is to the
Isothiourea-catalysed enantioselective pyrrolizine synthesis: synthetic and computational studies
作者:Daniel G. Stark、Patrick Williamson、Emma R. Gayner、Stefania F. Musolino、Ryan W. F. Kerr、James E. Taylor、Alexandra M. Z. Slawin、Timothy J. C. O'Riordan、Stuart A. Macgregor、Andrew D. Smith
DOI:10.1039/c6ob01557c
日期:——
The catalytic enantioselective synthesis of a range of cis-pyrrolizine carboxylate derivatives with outstanding stereocontrol (14 examples, >95 : 5 dr, >98 : 2 er) through an isothiourea-catalyzed intramolecular Michael addition-lactonisation and ring-opening approach from the corresponding enone acid is reported. An optimised and straightforward three-step synthetic route to the enone acid starting
通过异硫脲催化的分子内迈克尔加成-内酯化和开环方法,催化对映选择性合成一系列具有出色立体控制性的顺式吡咯嗪羧酸盐衍生物(14个实例,>95 : 5 dr,>98 : 2 er )据报道烯酮酸。描述了一种从容易获得的吡咯-2-甲醛中制备烯酮酸起始材料的优化且简单的三步合成路线,其中苯并四咪唑(5 mol%)被证明是对映选择性过程的最佳催化剂。用MeOH或一系列胺对吡咯嗪二氢吡喃酮产物进行开环,以优异的收率和对映选择性获得所需的产物。计算已被用来探索导致高立体控制的因素,所观察到的顺式立体异构体的形成预计在动力学和热力学上是有利的。
A General Method for the Enantioselective Synthesis of α-Chiral Heterocycles
作者:Phong Q. Le、Thien S. Nguyen、Jeremy A. May
DOI:10.1021/ol3030605
日期:2012.12.7
The enantioselective formation of stereocenters proximal to unprotected heterocycles has been accomplished. Thus, vinyl boronic acids are added to heterocycle-appended enones via a modified-BINOL catalyst. Catalyst design was key to enable a general reaction. High yields and useful er’s are observed for a host of common heteroaryls.
Novel bicycloannulation via tandem vinylation and intramolecular Diels-Alder reaction of five-membered heterocycles: a new approach to construction of psoralen and azapsoralen
Synthese d'heteryl-4 butene-3ones-2(A) par reaction AE de benzenesulfinyl-4 butene-3one-2 avec des furannes, pyrroles, imidazole, pyrazole et dimethylamino-6 fulvenes; par addition de Diels Alder les composes A sont ensuite transformes en furo [3,4-f] benzofurannes et -indoles; application a la synthese de psoralene et du lactame correspondant a partir de benzenesulfinyl-1 heptene-1yne-6one-3
合成这些 d'heteryl-4 butene-3ones-2(A) par 反应 AE de benzosulfinyl-4 butene-3one-2 avec des furanes, pyrroles, imidazole, pyrazole et dimethylamino-6 fulvenes; par add de Diels Alder les composes A sont ensuite transformes en furo [3,4-f] benzofuranes et -indoles; 申请 a la 合成补骨脂和内酰胺通讯员 a partir de benzosulfinyl-1 heptene-1yne-6one-3
A Novel Pseudo-Three-Component Synthetic Strategy for the Synthesis of 1,6-Dihydroazaazulenes via Cyclization of Pyrrolyl-enones
作者:Carlos Jesus Cortés-Garcia、Luis Chacón-García、Josue Valentin-Escalera、Ana Karen García-Dueñas、Cesar Rogelio Solorio-Alvarado、Claudia Contreras-Celedón
DOI:10.1055/a-1535-6085
日期:2021.9
A synthetic novel strategy involving a pseudo-three-component reaction to obtain 1,6-dihydroazaazulenes derivates via cyclization of pyrrolyl-enones was developed. This reaction is carried out under mild conditions from simple starting materials and catalyzed with ionic liquid. Notably, three new C–C bonds are formed in the one-pot process. The target molecules are of interest in medicinal chemistry