Rhodium-Catalyzed Ketone Methylation Using Methanol Under Mild Conditions: Formation of α-Branched Products†

The rhodium-catalyzed methylation of ketoneshas been accomplished using methanol as the methylating agent and the hydrogen-borrowing method. The sequence is notable for the relatively low temperatures that are required and for the ability of the reaction system to form α-branched products with ease. Doubly alkylated ketonescan be prepared from methyl ketonesand two different alcohols by using a sequential one-pot iridium- and rhodium-catalyzed process.