The document discusses the design of catalytic systems for selectively hydrogenating carbon-oxygen double bonds in furan derivatives. It describes the synthesis of pre-catalysts using cis-dichloride and unsaturation. New synthetic strategies were developed using dimethyl sulfoxide and 1,5-cyclooctadiene, yielding various products in high yields. Several new complexes were synthesized and characterized using NMR spectroscopy. Novel synthetic methods allowed tuning of ancillary ligands to control steric and electronic effects at the metal center.

1. Chemical solutions

2. Our focus Our effort focused on the design and development of efficient catalytic systems for the selective hydrogenation of C=O bonds in furan derivatives.

3. Synthesis of pre-catalysts Preparation of cis - dichloride 2. Unsaturation produces pre-catalyst. ( 1b ) 31 P{ 1 H} NMR (CDCl 3 ): δ 83.5 (t), 56.8 (t) (62% yield) ( 2a ) 31 P{ 1 H} NMR (CDCl 3 ): δ 130.3 (t), 118.5 (t) (48% yield) ( 2b ) 31 P{ 1 H} NMR (CDCl 3 ): δ 134.6 (t), 133.4 (t) (56% yield)

4. New Synthetic strategy with DMSO ( 6a ) 77% yield ( 7a ) 68% yield

5. New synthetic strategy with COD ( 8a ) 89 % yield ( 8b ) 82 % yield ( 9a ) 78 % yield ( 9b ) 45 % yield

6. Oxidative addition ( 7b ) 56 % yield ( 10a ) 59 % yield ( 10a ) 31 P{ 1 H} NMR (CDCl 3 ): δ 94 (d, Ir-Pyr 2 ), 92 (d, Ir-Ppyr 2 ). ( 7b ) 31 P{ 1 H} NMR (CDCl 3 ): δ 33.1 (d, Ir-PPh 2 ), 32.1 (d Ir-PPh 2 ).

7. Conclusions Several new complexes were synthesized and studied. Novel synthetic strategies were developed for the preparation of these systems. These new strategies incorporate the ability to tune ancillary ligands thus tuning the metal center for steric and electronic factors.