A simple and convenient protocol for the synthesis of seven- and eight-membered phosphorus heterocycles

<p>A simple procedure for the synthesis of eight-membered 6-(2-chloroethyl)/bis(2-chloroethyl)-amino-12-oxo-dibenzo[d,g][1,3,2]dioxaphosphocin 6-oxides (<b>3a–b</b>) and seven-membered 6-(2-chloroethyl)/bis-(2-chloroethyl)aminodibenzo[d,f][1,3,2]dioxaphosphepin 6-oxides (<b>5a–b</b>) from cyclocondensation of equimolar ratios of 2,2′-dihydroxybenzophenone (<b>1</b>) and 2,2′-dihydroxybiphenol (<b>4</b>), respectively with 2-chloroethylphosphonicdichloride (<b>2a</b>) and bis(2-chloroethyl)phosphoramidic dichloride (<b>2b</b>) in dry toluene in the presence of triethylamine at 45–50 °C is described. All synthesized compounds possessed significant growth inhibition for their antibacteria against ‘Bacillus subtilis’ and ‘Klebsiella pneumonia’ and antifungi activity on “Curvularia lunata” and “Aspergillus niger.”</p

Design, Synthesis, and Evaluation of a Neurokinin-1 Receptor-Targeted Near-IR Dye for Fluorescence-Guided Surgery of Neuroendocrine Cancers

The neurokinin-1 receptor (NK1R) is implicated in the growth and metastasis of many tumors, including cancers of the brain (e.g., gliomas, glioblastomas, and astrocytomas), skin (e.g., melanomas), and neuroendocrine tissues (cancers of the breast, stomach, pancreas, larynx, and colon). Because overexpression of NK1R has been reported in most of these malignancies, we have undertaken designing an NK1R-targeted near-infrared (NIR) fluorescent dye for fluorescence-guided surgeries of these cancers. We demonstrate here that an NK1R-binding ligand linked to the NIR dye LS288 selectively accumulates in NK1R-expressing tumor xenografts with high affinity (<i>K</i>_d = 13 nM), allowing intraoperative imaging of these cancers in live mice. Because tumor accumulation is nearly quantitatively blocked by excess unlabeled ligand, and because NK1R-negative tumors and normal tissues display virtually no uptake, we conclude that the observed tumor retention is NK1R-mediated. Results on the synthesis, in vitro characterization, and animal testing of NK1R-targeted NIR dye are presented

A Convergent Total Synthesis of the Potent Cephalostatin/Ritterazine Hybrid -25-<i>epi</i> Ritterostatin G_N1_N

The convergent synthesis of 25-<i>epi</i> ritterostatin G_N1_N is described for the first time, starting from hecogenin acetate (HA). Stereoselective dihydroxylation employing the chiral ligand (DHQ)₂PHAL was used as the key step to introduce the C25 <i>epi</i>-stereocenter on the north 1 segment. The title compound was obtained through a coupling reaction between the C3-keto-azide (cstat North 1) and North G

A Convergent Total Synthesis of the Potent Cephalostatin/Ritterazine Hybrid -25-<i>epi</i> Ritterostatin G_N1_N

The convergent synthesis of 25-<i>epi</i> ritterostatin G_N1_N is described for the first time, starting from hecogenin acetate (HA). Stereoselective dihydroxylation employing the chiral ligand (DHQ)₂PHAL was used as the key step to introduce the C25 <i>epi</i>-stereocenter on the north 1 segment. The title compound was obtained through a coupling reaction between the C3-keto-azide (cstat North 1) and North G

A Convergent Total Synthesis of the Potent Cephalostatin/Ritterazine Hybrid -25-<i>epi</i> Ritterostatin G_N1_N

The convergent synthesis of 25-<i>epi</i> ritterostatin G_N1_N is described for the first time, starting from hecogenin acetate (HA). Stereoselective dihydroxylation employing the chiral ligand (DHQ)₂PHAL was used as the key step to introduce the C25 <i>epi</i>-stereocenter on the north 1 segment. The title compound was obtained through a coupling reaction between the C3-keto-azide (cstat North 1) and North G

A Convergent Total Synthesis of the Potent Cephalostatin/Ritterazine Hybrid -25-<i>epi</i> Ritterostatin G_N1_N

The convergent synthesis of 25-<i>epi</i> ritterostatin G_N1_N is described for the first time, starting from hecogenin acetate (HA). Stereoselective dihydroxylation employing the chiral ligand (DHQ)₂PHAL was used as the key step to introduce the C25 <i>epi</i>-stereocenter on the north 1 segment. The title compound was obtained through a coupling reaction between the C3-keto-azide (cstat North 1) and North G

A Convergent Total Synthesis of the Potent Cephalostatin/Ritterazine Hybrid -25-<i>epi</i> Ritterostatin G_N1_N

The convergent synthesis of 25-<i>epi</i> ritterostatin G_N1_N is described for the first time, starting from hecogenin acetate (HA). Stereoselective dihydroxylation employing the chiral ligand (DHQ)₂PHAL was used as the key step to introduce the C25 <i>epi</i>-stereocenter on the north 1 segment. The title compound was obtained through a coupling reaction between the C3-keto-azide (cstat North 1) and North G