ABSTRACT
A tandem synthesis of quinazolinones from 2-aminobenzonitriles is demonstrated here by using an aliphatic alcohol-water system. For this transformation, a cheap and easily available cobalt salt and P(CH2CH2PPh2)3 (PP3) ligand were employed. The substrate scope, scalability, and synthesis of natural products exhibited the vitality of this protocol.
ABSTRACT
A practical method to synthesize α-alkylated arylacetonitriles from arylacetonitriles and alcohols without using any expensive transition metal complexes is demonstrated here. Following this base-catalysed sustainable procedure, various arylacetonitriles were successfully alkylated with different alcohols. The practical applicability of this protocol was extended by one-pot synthesis of important carboxylic acid derivatives.
ABSTRACT
Catalytic activities of a series of functional bipyridine-based RuII complexes in ß-alkylation of secondary alcohols using primary alcohols were investigated. Bifunctional RuII complex (3 a) bearing 6,6'-dihydroxy-2,2'-bipyridine (6DHBP) ligand exhibited the highest catalytic activity for this reaction. Using significantly lower catalyst loading (0.1â mol %) dehydrogenative carbon-carbon bond formation between numerous aromatic, aliphatic and heteroatom substituted alcohols were achieved with high selectivity. Notably, for the synthesis of ß-alkylated secondary alcohols this protocol is a rare one-pot strategy using a metal-ligand cooperative RuII system. Remarkably, complex 3 a demonstrated the highest reactivity compared to all the reported transition metal complexes in this reaction.
ABSTRACT
The atom economical borrowing hydrogen methodology enables the use of alcohols as alkylating agents for selective C-C bond formation. A bifunctional 2-(2-pyridyl-2-ol)-1,10-phenanthroline (phenpy-OH) based Ru(ii) complex (2) was found to be a highly efficient catalyst for the one-pot ß-alkylation of secondary alcohols with primary alcohols and double alkylation of cyclopentanol with different primary alcohols. Exploiting the metal-ligand cooperativity in complex 2, several aromatic, aliphatic and heteroatom substituted alcohols were selectively cross-coupled in high yields using significantly low catalyst loading (0.1 mol%). An outer-sphere mechanism is proposed for this system as exogenous PPh3 has no significant effect on the rate of the reaction. Notably, this is a rare one-pot strategy for ß-alkylation of secondary alcohols using a bifunctional Ru(ii)-complex. Moreover, this atom-economical methodology displayed the highest cumulative turn over frequency (TOF) among all the reported transition metal complexes in cross coupling of alcohols.
