Synthesis of a non-natural glucose-2-phosphate ester able to dupe the acc system of Agrobacterium fabrum

Sequential In Situ-Formed Kukhtin-Ramirez Adduct and P(NMe2)3-Catalyzed O-Phosphination of α-Dicarbonyls with P(O)-H

O-Phosphination of α-dicarbonyls via sequential in situ formation of a Kukhtin-Ramirez adduct and a P(NMe2)3-catalyzed process has been exploited for the synthesis of α-phosphoryloxy carbonyls. A range of P(O)-H derivatives, including diarylphosphine oxides, arylphosphinates, and phosphinates, are competent candidates to be introduced into the α-dicarbonyls in this transformation, and various α-phosphoryloxy carbonyls are obtained. This approach possesses advantages of mild conditions, simple operations, atom economy, high efficiency, and gram-scale synthesis, which make it promising in the synthesis toolbox.

Agrocinopine C, a Ti-plasmid-coded enzyme-product, is a 2-O, 6-O linked phosphodiester of D-Glucose and sucrose

Agrocinopine C is a small molecule found in crown gall tumours induced by pathogenic Agrobacterium radiobacter carrying the tumour-inducing plasmid pTi Bo542. This phosphodiester opine was isolated (at 0.02 g/100 g fresh wt.) from sunflower (Helianthus annuus L.) galls. It is structurally related to agrocinopine A and is a glucose-2-phosphodiester linked to the C6-hydroxy-methyl group of the glucose moiety of sucrose. Sugar-2-phosphates are uncommon in plant tissues, whether transformed by Agrobacterium or not. ¹H and ³¹P NMR signal multiplicity indicates five-fold anomeric complexity of agrocinopine C in solution, implying that the permeases taking up these sucrose-phosphodiesters could recognise any one of the five anomers. Data suggests that the open chain aldehyde forms of the 2-phosphorylated opines agrocinopine C and agrocinopine A and the corresponding phosphorylated glucose-2-phosphoramidate component of the antibiotic agrocin 84 play a central role in agrocin's selective toxicity to certain strains of Agrobacterium after uptake via Ti plasmid-encoded permeases.

B(C6F5)3-catalyzed O-H insertion reactions of diazoalkanes with phosphinic acids

A highly efficient base-, metal-, and oxidant-free catalytic O-H insertion reaction of diazoalkanes and phosphinic acids in the presence of B(C6F5)3 has been developed. This powerful methodology provides a green approach towards the synthesis of a broad spectrum of α-phosphoryloxy carbonyl compounds with good to excellent yields (up to 99% yield). The protocol features the advantages of operational simplicity, high atom economy, practicality, easy scalability and environmental friendliness.

Esters of Glucose-2-Phosphate: Occurrence and Chemistry

Phosphodiesters of glucose-2-phosphate (G2P) are found only in few natural compounds such as agrocinopine D and agrocin 84. Agrocinopine D is a G2P phosphodiester produced by plants infected by Agrobacterium fabrum C58 and recognized by the bacterial periplasmic binding protein AccA for being transported into the bacteria before cleavage by the phosphodiesterase AccF, releasing G2P, which promotes virulence by binding the repressor protein AccR. The G2P amide agrocin 84 is a natural antibiotic produced by the non-pathogenic Agrobacterium radiobacter K84 strain used as a biocontrol agent by competing with Agrobacterium fabrum C58. G2P esters are also found in irregular glycogen structures. The rare glucopyranosyl-2-phophoryl moiety found in agrocin 84 is the key structural signature enabling its action as a natural antibiotic. Likewise, G2P and G2P esters can also dupe the Agrobacterium agrocinopine catabolism cascade. Such observations illustrate the importance of G2P esters on which we have recently focused our interest. After a brief review of the reported phosphorylation coupling methods and the choice of carbohydrate building blocks used in G2P chemistry, a flexible access to glucose-2-phosphate esters using the phosphoramidite route is proposed.