Iron-Catalyzed anti-Selective Carbosilylation of Internal Alkynes.

Reported is the anti-selective carbosilylation of internal alkynes with silylborane and alkyl halides using a FeBr /DPPE catalyst system. The iron catalyst allows simultaneous introduction of a carbon electrophile and a silicon nucleophile to simple internal alkynes, including diaryl-, dialkyl-, and aryl/alkyl-substituted alkynes, in a highly stereoselective manner. Alkyl halides are applicable as the electrophiles, thereby enabling the synthesis of a variety of tetrasubstituted alkenylsilanes.

Reactivity of CA19-9 and CA125 in histological subtypes of epithelial ovarian tumors and ovarian endometriosis.

Previous reports have shown that some ovarian endometrioid adenocarcinomas and ovarian clear cell adenocarcinomas derive from ovarian endometriosis (OE), and that endocervical-like mucinous borderline ovarian tumors are associated with OE. We examined the relationship between the staging and histological subtypes of OE or epithelial ovarian tumors (EOT) and the serum levels of carbohydrate antigen 19-9 (CA19-9) and carbohydrate antigen 125 (CA125) to evaluate the potential of these markers for preoperative diagnosis. First, we analyzed the preoperative serum levels of CA19-9 and CA125 in 195 patients who were histopathologically diagnosed with OE or EOT.

Iron-catalyzed diboration and carboboration of alkynes.

An iron-catalyzed diboration reaction of alkynes with bis(pinacolato)diboron (B2pin2) and external borating agents (MeOB(OR)2) affords diverse symmetrical or unsymmetrical cis-1,2-diborylalkenes. The simple protocol for the diboration reaction can be extended to the iron-catalyzed carboboration of alkynes with primary and, unprecedentedly, secondary alkyl halides, affording various tetrasubstituted monoborylalkenes in a highly stereoselective manner. DFT calculations indicate that a boryliron intermediate adds across the triple bond of an alkyne to afford an alkenyliron intermediate, which can react with the external trapping agents, borates and alkyl halides.

Iron-catalyzed Negishi coupling toward an effective olefin synthesis.

A selective iron-catalyzed cross-coupling of alkyl halides with alkenylzinc reagents is described. Primary and secondary alkyl chlorides, bromides, and iodides take part in the reaction to give the corresponding olefins in good to excellent yields in a stereospecific manner. High functional group compatibility is also demonstrated by using combinations of substrates possessing rather reactive substituents.