Coordination-Induced Stereocontrol over Carbocations: Asymmetric Reductive Deoxygenation of Racemic Tertiary Alcohols
作者:Mayuko Isomura、David A. Petrone、Erick M. Carreira
DOI:10.1021/jacs.9b00862
日期:2019.3.20
intermediate tertiary carbocations. This approach has been implemented to achieve the first example of enantioselective reductive deoxygenation of tertiaryalcohols. This reduction occurs with high enantio- (up to 96% ee) and regioselectivity (up to >50:1 rr) by applying a novel Hantzsch ester analogue as a convenient hydride source. In-depth mechanistic studies support the involvement of a tertiary carbocation
Transition‐Metal‐Free Radical Hydrotrifluoromethylation of Alkynes
作者:Kiran Matcha、Andrey P. Antonchick
DOI:10.1002/ejoc.201800291
日期:2019.1.23
A combination of readily available and bench‐stable CF3SO2Na and tBuOOH was efficiently used for hydrotrifluoromethylation of alkynes. An excellent trans‐selectivity was demonstrated in the synthesis of alkenes. The developed mild reaction conditions allow the supression of the competing Meyer–Schuster‐type rearrangement.
容易获得且稳定的CF 3 SO 2 Na和t BuOOH的组合有效地用于炔烃的加氢三氟甲基化。在烯烃的合成中表现出优异的反选择性。发达的温和反应条件可以抑制竞争性的Meyer–Schuster型重排。
Brønsted acid mediated nitrogenation of propargylic alcohols: an efficient approach to alkenyl nitriles
作者:Xiaoqiang Huang、Ning Jiao
DOI:10.1039/c4ob00888j
日期:——
A novel and efficient approach to alkenyl nitriles from readily available propargylic alcohols has been developed. This nitrogenation reaction is transition-metal-free and could be conducted under air at ambient temperature, which makes this protocol promising and practical. Moreover, NH4Br is disclosed as an efficient additive to promote the stereoselectivity of this reaction.
Pd(II)-Catalyzed Highly Regio- and Stereoselective Assembly of C–C Double Bonds: An Efficient Method for the Synthesis of 2,4-Dihalo-1,3,5-trienes from Alkynols
A highly efficient method for the synthesis of 2,4-dihalo-1,3,5-trienes fromalkynols was developed. This chemistry allows access to multiple conjugated double bonds in a single step with high stereoselectivity.
A regio- and diastereoselective palladium-catalyzed cyclopropanation of norbornene derivatives with molecular oxygen as the sole oxidant
作者:Wanqing Wu、Huanfeng Jiang、Yang Gao、Huawen Huang、Wei Zeng、Derong Cao
DOI:10.1039/c2cc35124b
日期:——
A mild and efficient Pd-catalyzed cyclopropanation of norbornene derivatives with tertiary propargylic alcohols usingmolecularoxygen as the soleoxidant is described. This process allows quick and atom-economical assembly of various 1,2,3-trisubstituted cyclopropanes bearing alpha,beta-unsaturated ketone moieties in high yields as a single regio- and diastereoisomer.