Extremely short H···H distances and intermolecular hydrogen-bonding patterns of dialkyl α-aryl-α-(diphenylmethylamino)methanephosphonates

The synthesis of α-aryl-α-aminophosphonates and α-aryl-α-aminophosphine oxides by the microwave-assisted Pudovik reaction

“…A short intramolecular H(1)···H(10) distance in 5b appears to be nearly by −0.3 Å shorter than the sum of vdW radii (2.11(2) << 2.40), and is somewhat similar to those observed in other aminophosphonates [63]. No such short distance is seen in compound 5d , where all H···H contacts appear around or longer than the respective sums of van der Waals radii, and the only short attractive contact is in the H-bridge promoted dimer.…”

Microwave-assisted synthesis of α-aminophosphonates with sterically demanding α-aryl substituents

“…Table S4) can be summarized as leading to the same dimensions and conclusions as from those from the earlier, mostly roomtemperature structure determinations. [26] Neither phase transitions nor any relevant changes occur in the 173-295 K temperature range for 4b, 8b and 11b. As a measure of the similarity of these three pairs of independent structures at two sets of temperatures (295 K and 173 K) for 4b, 8b and 11b is provided by a least-square fit [27] of the C aryl -C a -N moiety.…”

“…These indicate that the low temperature structures are practically the same as reported. [26] This applies for the basic packing motifs (c.f. Table S5), too.…”

“…[23] Benzhydrylamine was also reacted with formylbenzoic acid and dimethyl phosphite, where 3-oxoisoindolin-1-ylphosphonate was synthesized in a moderate yield. [24] In most cases, these derivatives were synthesized by the Pudovik reaction of a-aryl imines with dialkyl phosphites, [25,26] also providing new information on the peculiar proximity H atoms. [26] In this paper, the synthesis of a-aryl-a-aminophosphonates by the solvent-and catalyst-free Kabachnik-Fields condensation of benzhydrylamine, aromatic aldehydes and dialkyl phosphites was revisited under MW irradiation.…”

“…[24] In most cases, these derivatives were synthesized by the Pudovik reaction of a-aryl imines with dialkyl phosphites, [25,26] also providing new information on the peculiar proximity H atoms. [26] In this paper, the synthesis of a-aryl-a-aminophosphonates by the solvent-and catalyst-free Kabachnik-Fields condensation of benzhydrylamine, aromatic aldehydes and dialkyl phosphites was revisited under MW irradiation. The investigation involved the preparation of the dialkyl a-aryl-a-(diphenylmethylamino)methanephosphonates, and the determination of the X-ray structures of a few of these products at low temperatures.…”