A catalytic enantioselective formal [2+2] cycloaddition between α‐halo acroleins and electronically diverse arylalkenes is described. In the presence of (S)‐oxazaborolidinium cation as the catalyst, densely functionalized cyclobutanes containing two vicinal tetrasubstituted stereocenters were produced in high yields and high diastereoselectivities with excellent enantioselectivities. Mechanistic studies
TANDEM TRANSFER HYDROGENATION AND OLIGOMERIZATION FOR HYDROCARBON PRODUCTION
申请人:California Institute of Technology
公开号:US20140200376A1
公开(公告)日:2014-07-17
The disclosure provides for hydrocarbon production by hydrogenation and oligomerizaton and, more particularly, to catalysis of alkanes and alkenes by a tandem transfer hydrogenation and oligomerization.
Iron Catalyzed Isomerization of
<scp>α‐Alkyl</scp>
Styrenes to Access Trisubstituted Alkenes
作者:Songgen Xu、Guixia Liu、Zheng Huang
DOI:10.1002/cjoc.202000492
日期:2021.3
supported by phosphine‐pyridine‐oxazoline (PPO) ligand. The protocol provides an atom‐efficient and operationally simple approach to trisubstituted alkenes in high yields with excellent regio‐ and stereoselectivities under mild conditions. The results of deuterium‐labelling and radical trap experiments are consistent with an iron‐hydride pathway involving reversible alkene insertion and β‐H elimination.
Catalytic Diastereoselective Hetero-Diels–Alder Reaction of α-Haloacroleins with Alkenes: Construction of 3,4-Dihydropyran
作者:Lei Zeng、Qian Lei、Weidong Rao、Lizhu Gao
DOI:10.1021/acs.orglett.2c00341
日期:2022.3.25
In this Letter, a catalyticdiastereoselective hetero-Diels–Alder reaction of α-haloacroleins with less polarized alkenes was developed, and the resulting 3,4-dihydropyrans were produced in high yields with a broad substate scope. Mechanism studies showed that 3,4-dihydropyran was produced from the ring expansion of cyclobutane, which was generated in the ring contraction of the initially formed unstable
Direct C–H Allylation of Unactivated Alkanes by Cooperative W/Cu Photocatalysis
作者:Pol Martínez-Balart、Balázs L. Tóth、Álvaro Velasco-Rubio、Martín Fañanás-Mastral
DOI:10.1021/acs.orglett.2c02887
日期:2022.9.23
enables the direct allylation of strong aliphatic C–H bonds with simple allylic chlorides. The method relies on a cooperative interaction of two metal catalysts in which the decatungstate anion acts as a hydrogen-atom abstractor generating a nucleophilic carbon-centered radical that engages in an SH2′ reaction with an activated allylic π-olefin–copper complex. Because of this dualcatalysis, the protocol
在这里,我们报告了一种光催化方法,该方法能够用简单的烯丙基氯化物直接烯丙基化强脂肪族 C-H 键。该方法依赖于两种金属催化剂的协同作用,其中十钨酸盐阴离子作为氢原子吸收剂产生亲核碳中心自由基,该自由基与活化的烯丙基π-烯烃-铜络合物发生S H 2' 反应。由于这种双重催化作用,该协议允许在温和条件下在短反应时间内对一系列化学原料和天然产物进行功能化。