Hydrophosphination of CO<sub>2</sub>and Subsequent Formate Transfer in the 1,3,2-Diazaphospholene-Catalyzed<i>N</i>-Formylation of Amines
作者:Che Chang Chong、Rei Kinjo
DOI:10.1002/anie.201505244
日期:2015.10.5
Hydrophosphination of CO2 with 1,3,2‐Diazaphospholene (NHP‐H; 1) afforded phosphorus formate (NHP‐OCOH; 2) through the formation of a bond between the electrophilic phosphorus atom in 1 and the oxygen atom from CO2, along with hydride transfer to the carbon atom of CO2. Transfer of the formate from 2 to Ph2SiH2 produced Ph2Si(OCHO)2 (3) in a reaction that could be carried out in a catalytic manner
Metal‐Free σ‐Bond Metathesis in 1,3,2‐Diazaphospholene‐Catalyzed Hydroboration of Carbonyl Compounds
作者:Che Chang Chong、Hajime Hirao、Rei Kinjo
DOI:10.1002/anie.201408760
日期:2015.1.2
The first metal‐free catalytic hydroboration of carbonyl derivatives has been developed in which a catalytic amount of 1,3,2‐diazaphospholene effectively promotes a hydroboration reaction of aliphatic and aromatic aldehydes and ketones. The reaction mechanism involves the cleavage of both the PO bond of the alkoxyphosphine intermediate and the BH bond of pinacolborane as well as the formation of
Metal-Free Catalytic Reduction of α,β-Unsaturated Esters by 1,3,2-Diazaphospholene and Subsequent C–C Coupling with Nitriles
作者:Che Chang Chong、Bin Rao、Rei Kinjo
DOI:10.1021/acscatal.7b01338
日期:2017.9.1
tautomerizes to saturated esters, while the P–O bond cleavage by HBpin via a formal σ-bond metathesis affords boryl enolate intermediate. The latter could undergo a further coupling reaction with nitriles to form substituted amino diesters or 1,3-imino esters, depending on α,β-unsaturatedester substrates. These catalytic reactions can also be performed in a one-pot manner, illustrating a protocol for metal-free
1,3,2‐Diazaphospholenes Catalyze the Conjugate Reduction of Substituted Acrylic Acids
作者:John H. Reed、Nicolai Cramer
DOI:10.1002/cctc.202000662
日期:2020.9.4
nucleophilicity and remarkablylow basicity of 1,3,2‐diazaphospholenes (DAPs) is exploited in a catalytic, metal‐free 1,4‐reduction of free α,β‐unsaturated carboxylic acids. Notably, the reduction occurs without a prior deprotonation of the carboxylic acid moiety and hence does not consume an additional hydride equivalent. This highlights the excellent nucleophilic character and low basicity of DAP‐hydrides
Chiral 1,3,2-Diazaphospholenes as Catalytic Molecular Hydrides for Enantioselective Conjugate Reductions
作者:Solène Miaskiewicz、John H. Reed、Pavel A. Donets、Caio C. Oliveira、Nicolai Cramer
DOI:10.1002/anie.201801300
日期:2018.4.3
of chiral, conformationally restricted methoxy‐1,3,2‐diazaphospholene catalysts is reported. We demonstrate their catalytic potential in asymmetric 1,4‐reductions of α,β‐unsaturated carbonyl derivatives, including enones, acyl pyrroles, and amides, which proceeded in enantioselectivities of up to 95.5:4.5 e.r.
1,2,3,2-二氮杂二膦烯原子具有极化的PH键,并以分子氢化物形式出现。本文报道了一类手性,构象受限的甲氧基-1,3,2-二氮杂磷腈催化剂。我们证明了它们在α,β-不饱和羰基衍生物(包括烯酮,酰基吡咯和酰胺)的不对称1,4-还原反应中的催化潜能,其对映选择性高达95.5:4.5 er