A series of novel gold(I) complexes bearing galactopyranoside-based N -heterocyclic carbene ligands have been synthesized via transmetalation of the corresponding Ag(I) complex. Gold(I) complexes have been characterized by NMR, Fourier transform infrared (FTIR), and elemental analysis. An exhaustive NMR analysis shows that the complexes are not stable when hydroxyl groups are deprotected. Catalytic studies, using the alkyne hydration as a model reaction, indicate that the synthesized complexes are active and reusable.

Bulky arylstannanes and bulky aroyl chlorides are good reaction partners for the synthesis of two-, three-, and even four-ortho-substituted benzophenones, in good to excellent isolated yields (47-91%). Three simple and direct routes, with differential advantages, are proposed: (i) a catalyst-free protocol, in o-dichlorobenzene (ODCB) at 180 °C; (ii) a room temperature protocol, using AlCl(3) (0.5 equiv), in dichloromethane (DCM); and (iii) a solvent-free, indium-promoted procedure. A radical mechanism is proposed for the indium-mediated reactions.

The solvent-free indium-promoted reaction of alkanoyl chlorides with sterically and electronically diverse arylstannanes is a simple and direct method for the regioselective synthesis of primary, secondary and tertiary alkyl aryl ketones in good to excellent isolated yields (42-84%) under mild and neutral conditions. The protocol is also adequate for the synthesis of aryl vinyl ketones. Reaction times are drastically reduced (from 3-32h to 10-70min) under ultrasonic irradiation. Evidences for the involvement of a homolytic aromatic ipso-substitution mechanism, in which indium metal acts as radical initiator, are presented. It is possible the transference of two aryl groups from tin, thus improving effective mass yield, working with diarylstannanes as starting substrates.