The reaction of the highly functionalized copper reagents RCu(CN)ZnI.BF3 with aldehydes

Preparation of Functionalized Amides Using Dicarbamoylzincs

We report a new convenient preparation of dicarbamoylzincs of type (R1 R2 NCO)2 Zn by the treatment of ZnCl2 and formamides R1 R2 NCHO with LiTMP in THF (15 °C, 15 min) or by the reaction of formamides R1 R2 NCHO with TMP2 Zn (25 °C, 16 h). This second method tolerates sensitive groups such as an ester, ketone or nitro function. Reaction of these dicarbamoylzincs with allylic, benzylic, aryl, alkenyl bromides, acid chlorides, aldehydes or enones provided various polyfunctional amides in 47-97 % yields. 13 C NMR characterization of these new carbamoylzinc derivatives is reported.

The total synthesis of siphonazole, a structurally unusual bis-oxazole natural product

The first synthesis of the unusual bis-oxazole natural product siphonazole is reported, both oxazole rings being constructed using rhodium carbene chemistry.

The Reaction of the α-Selenium Stabilized Copper Reagents ArSeCH2Cu(CN)ZnCI with Aldehydes

α-Arylseleno-substituted zinc and copper organometallics, in the presence of a Lewis acid, can react with aldehydes, ketones and enals with high chemoselectivity and regioselectivity.

Preparation of Organometallic Compounds from Highly Reactive Metal Powders

The formation of novel organometallic compounds by the reaction of organic substrates with finely divided metal powders represents a powerful tool for the synthetic chemist. The direct reaction with a zerovalent metal is the only viable method of synthesis for many of these compounds. Accordingly, chemists have been actively developing new methods for increasing the reactivity of metal powders toward organic substrates. Three principal approaches have been developed in recent years: the metal vaporization method, sonochemistry, and the preparation of finely divided metal powders by the reduction of metal salts. A number of new methods of synthesis have resulted from these studies.