P-O Bond Formation
Recent Literature
TfOH catalyzes wet and dry processes for converting phosphonate esters to
phosphonic acids in good yields. Whereas in the presence of water, a range of
alkyl-, alkenyl-, and aryl-substituted phosphonates can be hydrolyzed to the
corresponding phosphonic acids at 140°C, the conversion of dibenzyl phosphonates
to the corresponding phosphonic acids takes place smoothly at 80°C in toluene.
C. Li, Y. Saga, S.-y. Onozawa, S. Kobayashi, K. Sato, N. Fukaya, L.-B. Han, J. Org. Chem., 2020, 85, 14411–14419.
Ethyl bromoacetate mediates a facile and efficient synthesis of primary
phosphinamides from Ar2P(O)-H reagents with stable and readily
available ammonium carbonate as an ammonia source under mild and simple
conditions, without any metal catalyst or oxidant. Moreover, this method is also
appropriate for the reaction of Ar2P(O)-H with a variety of amines,
alcohols, and phenols.
Y. Tan, Y.-P. Han, Y. Zhang, H.-Y. Zhang, J. Zhao, S.-D. Yang, J. Org. Chem., 2022, 87,
3254-3264.
A rapid (<15 s) and mild (20 °C) alcoholysis of phosphorus trichloride in a
microflow reactor enables sequential direct substitution of the chlorine atoms
with alkoxyl/aryloxy groups to provide unsymmetrical H-phosphonates. The optimal
base concentration differed in each step, presumably attributed to differences
in the Brønsted basicity of the electrophilic intermediates.
Y. Tanaka, H. Kitamura, S. Fuse, J. Org. Chem., 2024, 89,
1777-1783.
The use of a P(V)-based Ψ-reagent enables an operationally simple, scalable, and
chemoselective method for the direct phosphorylation of alcohols. The method
provides access to valuable phosphorylated alcohols that would be otherwise
difficult to obtain.
M. Ociepa, K. W. Knouse, D. He, J. C. Vantourout, D. T. Flood, N. M. Padial,
J. S. Chen, B. B. Sanchez, E. J. Sturgell, B. Zheng, S. Qiu, M. A. Schmidt, M.
D. Eastgate, P. S. Baran, Org. Lett., 2021, 23,
9337-9342.
Monosubstituted phosphinic acids can be esterified with orthosilicates in
excellent yields. Whereas phosphinylidene-containing acids react selectively,
disubstituted phosphinic acids and phosphonic acids remain unchanged. This
method provides a convenient and general alternative to more commonly employed
reactions with diazomethane or carbodiimide.
Y. R. Dumond, R. L. Baker, J.-L. Montchamp,
Org. Lett., 2000, 2, 3341-3344.
Phosphorylation of amines, alcohols, and sulfoximines provides various
phosphoramidates, phosphorus triesters and sulfoximine-derived phosphoramidates
using molecular iodine as a catalyst and H2O2 as the sole
oxidant under mild reaction conditions.
J. Dhineshkumar, K. R. Prabhu, Org. Lett., 2013,
15, 6062-6065.
A simple visible-light photocatalytic reaction of N-alkoxypyridinium
salts with phosphites provides a broad range of phosphate esters under mild
conditions. The protocol was successfully applied to the synthesis of
biologically relevant structures.
A. Inial, F. Morlet-Savary, J. Lalevée, A.-C. Gaumont, S. Lakhdar,
Org. Lett., 2020, 22, 4404-4407.
A metal-, toxic chloride reagent-free activating strategy of various
phosphates with Tf2O and pyridine enables a facile synthesis of
functional phosphates such as alkyl phosphates, aza phosphates, thiophosphate,
and mixed diaryl phosphates via a transient phosphorylpyridin-1-ium species.
H. Huang, J. Ash, J. Y. Kang, Org. Lett.,
2018, 20, 4983-4941.
A selective three-step substitution transesterification starting with tris(2,2,2-trifluoroethyl)
phosphate enables the facile synthesis of mixed
unsymmetric phosphate triesters from three different alcohols. The substitution
of the trifluoroethoxy group at the phosphorus proceeds selectively in the
presence of DBU or lithium alkoxides.
K. Tsubaki, H. Shimooka, M. Kitamura, T. Okauchi,
Org. Lett., 2019, 21, 9779-9783.
Reaction of phosphorus oxychloride with a primary alcohol and triethylamine in
toluene, followed by filtration and treatment with steam, gives dialkyl
phosphates in good yield and essentially free from trialkyl phosphate impurities.
R. A. Aitken, C. J. Colett, S. T. E. Mesher, Synthesis, 2012, 44,
2515-2518.
An efficient electrophilic fluorination of secondary phosphine oxides with
Selectfluor provides direct access to phosphoric fluorides in good yield under
mild conditions. In addition, one-pot P-O bond construction is achieved in the
presence of water or alcohols to provide phosphinic acids or phosphinates.
Q. Chen, J. Zeng, X. Yan, Y. Huang, C. Wen, X. Liu, K. Zhang, J. Org. Chem.,
2016, 81, 10043-10048.
An electrochemical cross-dehydrogenative-coupling reaction between alcohols
and secondary phosphine oxides provides organophosphinates in an eco-friendly and efficient
manner at room temperature without the addition of any oxidant, metal
catalyst, or additive.
L. Deng, Y. Wang, H. Mei, Y. Pan, J. Han, J. Org. Chem., 2019, 84,
949-956.
Addition of P-H species to carbonyl groups, namely the Pudovik reaction,
normally delivers hydroxyl phosphorus compounds. A few systems starting from
phosphites provide the phosphates. Cs2CO3 mediates a highly selective synthesis of phosphinate derivatives starting
from phosphonate precursors.
Y. Qian, Q. Dai, Z. Li, Y. Liu, J. Zhang,
Org. Lett., 2020, 22, 4742–4748.
A series of 1-alkoxy-3-methyl- and 3,4-dimethyl-3-phospholene 1-oxides, as well
as 1-alkoxy-3-methylphospholane 1-oxides were prepared in good yields by a
microwave-assisted and [bmim][PF6]-catalyzed transesterification of
the corresponding methyl or ethyl esters.
N. Harsági, N. Z. Kiss, L. Drahos, G. Keglevich, Synthesis, 2022, 54,
3899-3905.
Bis(dimethylamino)phosphorodiamidate enables an efficient one-pot
cyclophosphorylation of vicinal cis-diol moieties of biologically
interesting polyols without the need for protecting group chemistry. The
reaction is amenable to large-scale reactions.
M. Yadav, R. Krishnamurthy,
Org. Lett., 2019, 21, 7400-7404.
Related
Copper catalysis allows the direct oxygen-arylation of dialkyl phosphonates with
diaryliodonium salts. This reaction proceeds with a wide range of phosphonates
and phosphoramidates under mild conditions and gives mixed alkyl aryl
phosphonates in very good yields and very good selectivity.
M. Fañanás-Mastral, B. L. Feringa, J. Am. Chem. Soc., 2014,
136, 9894-9897.