The reaction of silyldibromomethyllithium with aromatic imines provides r-amino acylsilanes via a bromo aziridine intermediate upon quenching the reaction with water. Alternatively, treatment of the bromo aziridine intermediate with various Grignard reagents or lithium aluminum hydride permits the nucleophilic displacement of the halogen to furnish substituted silyl aziridines.Aziridines are an important class of three-membered Nheterocyclic compounds which serve as versatile intermediates in organic synthesis. 1 Their inherent ring strain activates the carbon-nitrogen bond, and they often serve as good electrophiles. Consequently, aziridine-containing natural products often exhibit strong biological activities because the aziridine motif can act as a powerful alkylating agent for DNA. 2 Recently, Aggarwal et al. have reported that silyl aziridines can serve as useful intermediates for the synthesis of aziridine derivatives. 3 Here we wish to report a novel synthesis of silyl aziridines via a three-component coupling reaction with silyldibromomethyllithium. Additionally, this procedure al-

A convergent synthesis of a pyrimidine core has been achieved. Treatment of alpha,alpha-dibromo oxime ethers, which are easily derived from the corresponding esters, with a variety of Grignard reagents provides trisubstituted pyrimidines in good yields. This new method offers an easy access to functionalized pyrimidines.

[reaction: see text] Treatment of formyl alpha,beta-enones with a TiCl(4)-R(4)NX combination induces an intramolecular aldol cyclization to furnish 2-acyl-3-halocyclohexanol with three controlled consecutive stereogenic centers. The reaction of bis-alpha,beta-enones with the combination provides cyclic diketones with high stereoselectivity via an intramolecular Michael addition reaction.

A one‐carbon unit is lost in the condensation of α‐chloro oxime ethers induced by lithium diisopropylamide [Eq. (1)]. This reaction, which provides alkynyl oxime ethers in good yields, is proposed to proceed via a 2‐(iminomethyl)azacyclobutadiene intermediate.

A synthesis of alpha-keto acylsilanes, where 2-bromo-2H-azirine participates as a key intermediate, is reported. The reaction of silyldibromomethyllithium with aryl nitriles provides alpha-keto acylsilanes in good yields. Interestingly, silyldichloromethyllithium induces aza-1,3-Brook rearrangement of the silyl group in th reaction with nitriles. The rearrangement enables a three-component coupling reaction in a one-pot operation.