Delivery of a BET protein degrader via a CEACAM6-targeted antibody-drug conjugate inhibits tumour growth in pancreatic cancer models.

Pancreatic ductal adenocarcinoma (PDAC) has the worst prognosis of all cancers. To improve PDAC therapy, we establish screening systems based on organoid and co-culture technologies and find a payload of antibody-drug conjugate (ADC), a bromodomain and extra-terminal (BET) protein degrader named EBET. We select CEACAM6/CD66c as an ADC target and developed an antibody, #84.

Fe-Catalyzed C-C Bond Construction from Olefins via Radicals.

This Article details the development of the iron-catalyzed conversion of olefins to radicals and their subsequent use in the construction of C-C bonds. Optimization of a reductive diene cyclization led to the development of an intermolecular cross-coupling of electronically-differentiated donor and acceptor olefins. Although the substitution on the donor olefins was initially limited to alkyl and aryl groups, additional efforts culminated in the expansion of the scope of the substitution to various heteroatom-based functionalities, providing a unified olefin reactivity.

Stainless-Steel Ball-Milling Method for Hydro-/Deutero-genation using H2O/D2O as a Hydrogen/Deuterium Source.

A one-pot continuous-flow method for hydrogen (deuterium) generation and subsequent hydrogenation (deuterogenation) was developed using a stainless-steel (SUS304)-mediated ball-milling approach. SUS304, especially zero-valent Cr and Ni as constituents of the SUS304, and mechanochemical processing played crucial roles in the development of the reactions.

Gold-Catalyzed Benzylic Azidation of Phthalans and Isochromans and Subsequent FeCl3-Catalyzed Nucleophilic Substitutions.

The benzylic positions of the phthalan and isochroman derivatives (1) as benzene-fused cyclic ethers effectively underwent gold-catalyzed direct azidation using trimethylsilylazide (TMSN3) to give the corresponding 1-azidated products (2) possessing the N,O-acetal partial structure. The azido group of the N,O-acetal behaved as a leaving group in the presence of catalytic iron(III) chloride, and 1-aryl or allyl phthalan and isochroman derivatives were obtained by nucleophilic arylation or allylation, respectively. Meanwhile, a double nucleophilic substitution toward the 1-azidated products (2) occurred at the 1-position using indole derivatives as a nucleophile accompanied by elimination of the azido group and subsequent ring opening of the cyclic ether nucleus produced the bisindolylarylmethane derivatives.

Functionalized olefin cross-coupling to construct carbon-carbon bonds.

Carbon-carbon (C-C) bonds form the backbone of many important molecules, including polymers, dyes and pharmaceutical agents. The development of new methods to create these essential connections in a rapid and practical fashion has been the focus of numerous organic chemists. This endeavour relies heavily on the ability to form C-C bonds in the presence of sensitive functional groups and congested structural environments.

Palau'chlor: a practical and reactive chlorinating reagent.

Unlike its other halogen atom siblings, the utility of chlorinated arenes and (hetero)arenes are twofold: they are useful in tuning electronic structure as well as acting as points for diversification via cross-coupling. Herein we report the invention of a new guanidine-based chlorinating reagent, CBMG or "Palau'chlor", inspired by a key chlorospirocyclization en route to pyrrole imidazole alkaloids. This direct, mild, operationally simple, and safe chlorinating method is compatible with a range of nitrogen-containing heterocycles as well as select classes of arenes, conjugated π-systems, sulfonamides, and silyl enol ethers.

C-H methylation of heteroarenes inspired by radical SAM methyl transferase.

A practical C-H functionalization method for the methylation of heteroarenes is presented. Inspiration from Nature's methylating agent, S-adenosylmethionine (SAM), allowed for the design and development of zinc bis(phenylsulfonylmethanesulfinate), or PSMS. The action of PSMS on a heteroarene generates a (phenylsulfonyl)methylated intermediate that can be easily separated from unreacted starting material.

A practical and catalytic reductive olefin coupling.

A redox-economic method for the direct coupling of olefins that uses an inexpensive iron catalyst and a silane reducing agent is reported. Thus, unactivated olefins can be joined directly to electron-deficient olefins in both intra- and intermolecular settings to generate hindered bicyclic systems, vicinal quaternary centers, and even cyclopropanes in good yield. The reaction is not sensitive to oxygen or moisture and has been performed on gram-scale.

Karlotoxin synthetic studies: concise synthesis of a C(42-63) B-ring tetrahydropyran fragment.

Starting from natural D-mannose, a C(42-63) B-ring tetrahydropyran fragment in karlotoxin 2 has been prepared via a common THP intermediate in a concise manner. -selective Julia-Kocienski olefination efficiently assembled a C(51-63) chlorodiene subunit and a C(42-50) tetrahydropyran segment.

Chemoselective hydrogenation reaction of unsaturated bonds in the presence of an o-nitrobenzenesulfonyl group.

Chemoselective hydrogenation of unsaturated compounds bearing an o-nitrobenzenesulfonyl (Ns)-amide moiety, affording the corresponding saturated compounds, was accomplished efficiently without loss of the nitro group by using the Pd/MS3A catalyst and a H2 balloon. Partial hydrogenation of alkynes bearing an Ns group to corresponding cis alkenes was achieved with the combination of the Pd/BN catalyst and an additive (diethylenetriamine or acetic acid).

Iron-catalyzed chemoselective azidation of benzylic silyl ethers.

Azidation: siloxy groups derived from secondary and tertiary benzyl alcohols can be transformed into azide groups at room temperature using TMSN(3) in the presence of an iron catalyst (TMS=trimethylsilyl). Secondary and tertiary benzylic silyl ethers can be transformed in the presence of primary silyl ethers, and other reactive functional groups, such as alkyl chlorides, α,β-unsaturated esters, and aldehydes, are stable under the reaction conditions.

Stereo- and regioselective direct multi-deuterium-labeling methods for sugars.

Deuterium-labeled sugars can be utilized as powerful tools for the architectural analyses of high-sugar-containing molecules represented by the nucleic acids and glycoproteins, and chiral building blocks for the syntheses of new drug candidates (heavy drugs) due to their potential characteristics, such as simplifying the (1)H NMR spectra and the stability of C-D bonds compared with C-H bonds. We have established a direct and efficient synthetic method of deuterated sugars from non-labeled sugars by using the heterogeneous Ru/C-catalyzed H-D exchange reaction in D(2)O under a hydrogen atmosphere with perfect chemo- and stereoselectivities. The direct H-D exchange reaction can selectively proceed on carbons adjacent to the free hydroxyl groups, and the deuterium labeling of various pyranosides (such as glucose and disaccharides), as well as furanosides, represented by ribose and deoxyribose was realized.

DIBAL-mediated reductive transformation of trans-dimethyl tartrate acetonide into ε-hydroxy α,β-unsaturated ester and its derivatives.

Stepwise, selective DIBAL reduction of the acetonide diester derived from tartaric acid followed by the Horner-Emmons reaction effectively provided desymmetrized hydroxy mono-olefination products in a one-pot operation.

Geranylgeranylacetone induces cyclooxygenase-2 expression in cultured rat gastric epithelial cells through NF-kappaB.

Geranylgeranylacetone (GGA) effectively protects the gastric mucosa against noxious agents. The precise mechanisms underlying the gastroprotective actions of GGA are not known. To elucidate the precise mechanism of GGA, the effect of GGA treatment on COX-2 expression in rat gastric epithelial (RGM1) cells was investigated.

(2E,6Z,10E)-7-hydroxymethyl-3,11,15-trimethyl-2,6,10,14-hexadecatetraen-1-ol (Plaunotol) increases cyclooxygenase-2 expression via nuclear factor kappaB and cyclic AMP response element in rat gastric epithelial cells.

Plaunotol, [(2E,6Z,10E)-7-hydroxymethyl-3,11,15-trimethyl-2,6,10,14-hexadecatetraen-1-ol], a gastroprotective agent, increases the prostaglandin production in the gastric mucosa and accelerates ulcer healing. The precise mechanisms underlying the gastroprotective actions by plaunotol are not known. On the other hand, cyclooxygenase (COX)-2 is a key enzyme in PGE(2) production and its induction is thought to have an important role in ulcer healing.

Gastro-protective agent rebamipide induces cyclooxygenease-2 (COX-2) in gastric epithelial cells.

Cyclooxyngease-2 (COX-2) is a key enzyme in prostaglandin (PG) synthesis, and COX-2 induction plays an important role in the healing of gastric ulceration. Rebamipide is a gastro-protective agent and attenuates the activity of neutrophils. A number of reports have shown that rebamipide treatment increases PG production in the gastric mucosa {in vivo}.