Photoredox/Cobalt Dual‐Catalyzed Decarboxylative Elimination of Carboxylic Acids: Development and Mechanistic Insight
作者:Kaitie C. Cartwright、Ebbin Joseph、Chelsea G. Comadoll、Jon A. Tunge
DOI:10.1002/chem.202001952
日期:2020.9.25
Recently, dual‐catalytic strategies towards the decarboxylative elimination of carboxylicacids have gained attention. Our lab previously reported a photoredox/cobaloxime dual catalytic method that allows the synthesis of enamides and enecarbamates directly from N‐acyl amino acids and avoids the use of any stoichiometric reagents. Further development, detailed herein, has improved upon this transformation's
Calcium-Catalyzed Direct Amination of π-Activated Alcohols
作者:Stefan Haubenreisser、Meike Niggemann
DOI:10.1002/adsc.201000768
日期:2011.2.11
A calcium-catalyzed direct amination of π-activated alcohols with different nitrogen nucleophiles under very mild reaction conditions is presented. The high reactivity of the calcium catalyst allows for an efficient conversion of secondary and tertiary benzylic and allylic as well as tertiary propargylic alcohols. Nitrogen nucleophiles such as carbamates, tosylamides and anilines are readily alkylated
Comparative studies about the hydroamination of unactivatedalkenes and dienes catalyzed by either cationic gold(I) triphenyl phosphite complexes or silver salts were performed using sulfonamides, anilines and carbamates as nucleophiles. Gold-catalyzed reactions generally, need lower loadings than those carried out with silver salts. Simple alkenes react only with sulfonamides and weak aromatic amines
Zirconium-Catalyzed Intermolecular Hydroamination of Unactivated Olefins
作者:Li-Wen Xu、Chun-Gu Xia、Lei Yang、Wei Zhou、Yue-Hua Gao、Wei Sun
DOI:10.1055/s-0028-1088151
日期:2009.4
Highly efficienthydroamination reactions of sulfonamides, carboxamides, and carbamates with unactivatedolefins catalyzed by simple and inexpensive zirconium salts under mild reaction conditions were presented for the practical preparation of various amines. These processes gave good to excellent yields of the addition products in Markovnikov addition fashion.
The first example of simple Re2O7-catalyzed direct dehydrative coupling between allylic alcohols with electron-deficient amines has been achieved under mild and open flask conditions. The protocol has also been successfully applied to benzylic and propargylic alcohols. The mechanistic proof for the SN1-type process has also been provided.
在温和和开放的烧瓶条件下,已经实现了烯丙基醇与缺电子的胺之间简单的Re 2 O 7催化的直接脱水偶合的第一个例子。该协议也已成功应用于苄醇和炔丙基醇。还提供了用于S N 1型过程的机理证明。