A novel Rh(I)-catalyzed approach to synthesizing functionalized (E,Z) dienal compounds has been developed via tandem transformation where a stereoselective hydrogen transfer follows a propargyl Claisen rearrangement. Z-Stereochemistry of the first double bond suggests the involvement of a six-membered cyclic intermediate whereas the E-stereochemistry of the second double bond stems from the subsequent protodemetallation step giving an (E,Z)-dienal. The reaction may be represented by the following sequence. ##STR00001##

meta-Substituted 3-phenylpropanal derivatives useful in providing watery-marine, floral-aldehydic notes.

meta-Substituted 3-phenylpropanal derivatives useful in providing watery-marine, floral-aldehydic notes.

A novel Rh(I)-catalyzed approach to synthesizing functionalized (E,Z) dienal compounds has been developed via tandem transformation where a stereoselective hydrogen transfer follows a propargyl Claisen rearrangement. Z-Stereochemistry of the first double bond suggests the involvement of a six-membered cyclic intermediate whereas the E-stereochemistry of the second double bond stems from the subsequent protodemetallation step giving an (E,Z)-dienal. The reaction may be represented by the following sequence.

##STR00001##

A novel Rh(I)-catalyzed approach to synthesizing functionalized (E,Z) dienal compounds has been developed via tandem transformation where a stereoselective hydrogen transfer follows a propargyl Claisen rearrangement. Z-Stereochemistry of the first double bond suggests the involvement of a six-membered cyclic intermediate whereas the E-stereochemistry of the second double bond stems from the subsequent protodemetallation step giving an (E,Z)-dienal. The reaction may be represented by the following sequence.

##STR00001##

Methods described herein relate to a partial reduction of esters to aldehydes or nitrogen-containing products facilitated by Group IV transition metal catalysts, using hydrosilanes as the reductant. The method allows the product to be preserved at the aldehyde oxidation level rather than over-reduction to the corresponding alcohol and can result in the formation of value-added recycled monomers. Methods described herein can be used for the direct catalytic chemical upcycling of polyester plastic waste through depolymerization transformations.

Methods described herein relate to a partial reduction of esters to aldehydes or nitrogen-containing products facilitated by Group IV transition metal catalysts, using hydrosilanes as the reductant. The method allows the product to be preserved at the aldehyde oxidation level rather than over-reduction to the corresponding alcohol and can result in the formation of value-added recycled monomers. Methods described herein can be used for the direct catalytic chemical upcycling of polyester plastic waste through depolymerization transformations.

A novel Rh(I)-catalyzed approach to synthesizing functionalized (E,Z) dienal compounds has been developed via tandem transformation where a stereoselective hydrogen transfer follows a propargyl Claisen rearrangement. Z-Stereochemistry of the first double bond suggests the involvement of a six-membered cyclic intermediate whereas the E-stereochemistry of the second double bond stems from the subsequent protodemetallation step giving an (E,Z)-dienal. The reaction may be represented by the following sequence. ##STR00001##

A novel Rh(I)-catalyzed approach to synthesizing functionalized (E,Z) dienal compounds has been developed via tandem transformation where a stereoselective hydrogen transfer follows a propargyl Claisen rearrangement. Z-Stereochemistry of the first double bond suggests the involvement of a six-membered cyclic intermediate whereas the E-stereochemistry of the second double bond stems from the subsequent protodemetallation step giving an (E,Z)-dienal. The reaction may be represented by the following sequence. ##STR00001##