Phosphite Esters: Reagents for Exploring S-Nitrosothiol Chemistry

Reaction of Amide and Sodium Azide for the Synthesis of Acyl Azide, Urea, and Iminophosphorane

Amides reacted with NaN₃ to give the acyl azides in DMF at 25 °C and produce the symmetrical ureas in THF/H₂O at 80 °C via the sequential reaction of acyl substitution and Curtius rearrangement. All acyl azides were also obtained from the secondary amides via sequential reaction of p-toluenesulfonyl chloride and NaN₃. In addition, keto-stabilized iminophosphoranes were prepared from a one-pot reaction of amides, NaN₃, and phosphines.

Coupling of 1-Chloro-N,N-diisopropylphosphanamine-Based Reagents with Alcohols and Thiosulfonates: A Precise Construction of O-P(O)-S Bonds

Herein, we present the first mild, one-step direct synthesis of mixed phosphorothioates through selective generation of O-P(O)-S bonds at rt under additive-free condition. Further, reactions of different model natural products with 1,1-dichloro-N,N-diisopropylphosphanamine helped to present an alternative dimerization strategy. The synthetic utility of the methodology was extended for the synthesis of mixed phosphoroselenoates as well. The potential of the reaction was further demonstrated for the synthesis of mixed phosphorothioate bearing two different alcohols.

Sulfonyl-Promoted Michaelis-Arbuzov-Type Reaction: An Approach to S/Se-P Bonds

By facilitating the chemical conversion of thiols to thiosulfonates, phosphoramidite/phosphite bearing sp³-hybridized carbon serves as an ideal coupling material to forge new connections at room temperature. In this work, a functional group-induced, additive-free, novel, S-P bond-forming approach is presented. This protocol exhibits good functional group tolerance with wide applications that include phosphorylation of cysteine derivatives, development of a one-pot approach to mixed unsymmetrical thiophosphonates, and extension of the concept to different Se-P bonds. Meticulously, our reaction also generated a S-P bond against cyclic 1,2-dithiane-1-dioxide in a byproduct-free manner. These Michaelis-Arbuzov-type reactions are easy to conduct, work efficiently in a reduced reaction time, and are applicable to gram-scale preparation as well.

Interweaving Visible-Light and Iron Catalysis for Nitrene Formation and Transformation with Dioxazolones

Herein, visible-light-driven iron-catalyzed nitrene transfer reactions with dioxazolones for intermolecular C(sp³ )-N, N=S, and N=P bond formation are described. These reactions occur with exogenous-ligand-free process and feature satisfactory to excellent yields (up to 99 %), an ample substrate scope (109 examples) under mild reaction conditions. In contrast to intramolecular C-H amidations strategies, an intermolecular regioselective C-H amidation via visible-light-induced nitrene transfer reactions is devised. Mechanistic studies indicate that the reaction proceeds via a radical pathway. Computational studies show that the decarboxylation of dioxazolone depends on the conversion of ground sextet state dioxazolone-bounding iron species to quartet spin state via visible-light irradiation.

Phosphorus-containing amino acids with a P–C bond in the side chain or a P–O, P–S or P–N bond: from synthesis to applications

Strategies for the preparation of phosphorus-containing amino acids and their utility in the organic chemistry, physico-chemistry, agrochemistry, and pharmacology fields are reported.