- Palladium/Xiao-Phos-Catalyzed Kinetic Resolution of sec-Phosphine Oxides by P-Benzylation
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P-stereogenic tert- and sec-phosphines have wide applications in asymmetric catalysis, materials, and pharmaceutical chemistry, however, their practical synthesis still constitutes a significant challenge. Herein, a successful kinetic resolution of rac-se
- Dai, Qiang,Liu, Lu,Zhang, Junliang
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supporting information
p. 27247 - 27252
(2021/11/17)
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- Selective Conversion of Benzylic Phosphates into Diarylmethanes Through Al(OTf)3-Catalyzed Friedel–Crafts-Type Benzylation
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Al(OTf)3 was identified as a high-performance catalyst for Friedel–Crafts-type benzylation using benzylic phosphates as electrophiles. The reaction proceeded even with 0.2 mol-% of the catalyst. A series of diarylmethanes (21 examples) was obtained in moderate to high yield. The catalyst showed unique chemoselectivity, preferentially converting the benzylic phosphate motif, even with a benzylic acetate group existed in the same molecule.
- Yurino, Taiga,Hachiya, Asuka,Suzuki, Keisuke,Ohkuma, Takeshi
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p. 2225 - 2232
(2020/04/16)
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- BuLi-triggered phospha-Brook rearrangement: Efficient synthesis of organophosphates from ketones and aldehydes
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A variety of organophosphates are synthesized from n-BuLi-triggered, (additional) solvent-free reactions of diethyl phosphite with both activated/unactivated ketones and aldehydes preferably at room temperature via phospha-Brook rearrangement. We could successfully synthesize the naphthylic/allylic phosphates using this approach.
- Pallikonda, Gangaram,Santosh, Ranga,Ghosal, Subhas,Chakravarty, Manab
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p. 3796 - 3798
(2015/06/08)
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- Synthesis of diarylmethanes through palladium-catalyzed coupling of benzylic phosphates with arylsilanes
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An efficient approach to the benzylation of arenes has been developed. The reactions described provide straightforward access to diarylmethanes through Pd-catalyzed coupling of benzylic phosphates with arylsilanes in good to excellent yields. The reaction tolerates a wide range of functionalities such as halide, alkoxyl, and nitro groups.
- Zhang, Pengbo,Xu, Jian,Gao, Yuzhen,Li, Xueqin,Tang, Guo,Zhao, Yufen
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p. 2928 - 2932
(2015/01/16)
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- Photochemistry of phosphate esters: An efficient method for the generation of electrophiles
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The photochemical cleavage of benzyl diethyl phosphates, 1a-g, has been examined in tert-butyl alcohol, which produces the corresponding benzyl tert-butyl ether as the major solvolysis product upon direct irradiation. The multiplicity of the reactive excited state has been established as the singlet state. Evidence favoring an intermediate benzyl cation-phosphate ion pair formed from photofragmentation includes oxygen-18 scrambling, racemization of chiral benzyl phosphates, and substituent effects on the rate of reaction. The existence of an electrophilic intermediate is further supported by a linear free energy relationship for the rate of disappearance of 1, kdis, with Hammett σ, which gave a ρ value of -0.90 and for the rate of appearance of 2, kapp, a Hammett ρ value of -0.97. Possible mechanisms including an electron transfer either before or after homolysis or simple heterolysis of the ester bond are evaluated.
- Givens, Richard S.,Matuszewski, Bogdan,Athey, Phillip S.,Robert Stoner
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p. 6016 - 6021
(2007/10/02)
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