Lithium amidoborane (LiNH2BH3, LiAB for short), is capable of chemoselectively reducing α,β-unsaturatedketones to the corresponding allylicalcohols at ambient temperature. A mechanistic study shows that the reduction is via a double hydrogen transfer process. The protic H(N) and hydridic H(B) in amidoborane add to the O and C sites of the carbonyl group, respectively.
Tuning the Product Selectivity of the α-Alkylation of Ketones with Primary Alcohols using Oxidized Titanium Nitride Photocatalysts and Visible Light
作者:Peifeng Li、Gang Xiao、Yilin Zhao、Haijia Su
DOI:10.1021/acscatal.9b04921
日期:2020.3.20
α-alkylated ketones and enones is an attractive procedure for C–C bondformation. High reaction temperatures are always needed for heterogeneous catalysisusing non-noble metals, and switching product selectivity in one catalysis system remains a great challenge. In the present study, a visible-light-driven procedure for this reaction is proposed, using oxidized TiN photocatalysts under mild conditions, whereby
Rhodium-Catalyzed Enantioselective Isomerization of Secondary Allylic Alcohols
作者:Tang-Lin Liu、Teng Wei Ng、Yu Zhao
DOI:10.1021/jacs.7b01096
日期:2017.3.15
The first catalytic enantioselective isomerization of secondary allylicalcohols to access ketones with a α-tertiary stereocenter is presented. The racemic allylicalcohol substrates can be converted to the enantioenriched ketone products in a stereoconvergent fashion. The use of commercially available catalysts and mild reaction conditions makes this an attractive method in stereoselective synthesis
Dual Photoredox/Cobalt-Catalyzed Reductive Cyclization of Alkynals
作者:Kento Nakamura、Hina Nishigaki、Yoshihiro Sato
DOI:10.1021/acscatal.3c06206
日期:2024.3.1
alkynals using H2O for the catalyst turnover. This method was applied to aliphatic and aromatic aldehydes for five-, six-, and seven-membered (heterocyclic) ring formation with various substitutions on alkyne units. This H2O-added protocol was further developed into a one-pot transformation fromacetals through in situ generated aldehydes, which shortened the synthetic path of the reaction.
取代环醇是药学上必需的支架之一。在这里,我们报道了使用 H 2 O进行催化剂周转的光氧化还原/钴催化的炔醛还原环化。该方法适用于脂肪族和芳香族醛,形成五元、六元和七元(杂环)环,并在炔单元上进行各种取代。这种添加H 2 O的方案进一步发展为从缩醛到原位生成醛的一锅转化,从而缩短了反应的合成路径。
Palladium-Catalyzed Enantioselective Oxidation of Chiral Secondary Alcohols: Access to Both Enantiomeric Series
作者:David C. Ebner、Raissa M. Trend、Cédric Genet、Matthew J. McGrath、Peter O'Brien、Brian M. Stoltz