Novel, chiral Lewisbase organocatalysts, which displayed poor enantioselection in the hydrosilylation of N-aryl β-enamino esters, were found to be the catalysts of choice in the hydrosilylation of α-imino esters. In the presence of 10 mol-% of the best catalyst, various α-imino esters underwent enantioselectivehydrosilylation to provide a wide range of chiral α-amino esters with good yields (up to
from a rhodium center to imine substrates in a biomimetic way. Under both transfer hydrogenation and reductiveamination reaction conditions, the catalyst exhibited good selectivity towards CN bonds. With the catalyst, 34 imines were transfer hydrogenated to corresponding amines and a key intermediate of retigabine was prepared via reductiveamination in a greener way. According to the NMR observations
将基于金属和键合辅因子模拟物之间合作的策略应用于 CN 键的转移氢化。我们设计并合成了一种含有 1,3-二甲基苯并咪唑部分的铑配合物,它可以以仿生的方式将氢化物从铑中心转移到亚胺底物上。在转移氢化和还原胺化反应条件下,催化剂对C N 键表现出良好的选择性。使用该催化剂,34个亚胺被转移氢化成相应的胺,并通过还原胺化以更绿色的方式制备了瑞替加滨的关键中间体。根据核磁共振观察和同位素实验,提出了这种仿生还原碳氮键的合理机制。
The First General, Highly Enantioselective Lewis Base Organo- catalyzed Hydrosilylation of Benzoxazinones and Quinoxalinones
The first general, highlyenantioselectivehydrosilylation of benzoxazinones and quinoxalinones has been developed. The chiral Lewisbase organocatalysts that are readily accessible from (1S,2R)‐ephedrine and (1R,2S)‐ephedrine promoted the title reaction to afford various chiral dihydrobenzoxazinones and dihydroquinoxalinones with good yields as well as good enantioselectivities.
dinucleotide (NADH) model in a redox‐active molecular flask, we combined biomimetic hydrogenation with in situ regeneration of the active site in a one‐pot transformation using light as a clean energy source. This molecular flask facilitates the encapsulation of benzoxazinones for biomimetic hydrogenation of the substrates within the inner space of the flask using the active sites of the NADHmodels. The redox‐active