Catalytic reductive coupling

Catalytic Reductive Coupling of Carbonyl Compounds -The Pinacol Coupling Reaction and Beyond... 

Catalytic Reductive Coupling of Alkenes and Alkynes to Carbonyl Compounds and Imines Mediated by Hydrogen... 

Abstract Significant advances have been made in the study of catalytic reductive coupling of alkenes and alkynes over the past 10 years. This work will discuss the progress made in early transition metal and lanthanide series catalytic processes using alkyl metals or silanes as the stoichiometric reductants and the progress made in the use of late transition metals for the same reactions using silanes, stannanes and borohydrides as the reductant. The mechanisms for the reactions are discussed along with stereoselective variants of the reactions. 

Hirao T (2007) Catalytic Reductive Coupling of Carbonyl Compounds - The Pinacol Coupling Reaction and Beyond. 279 53-75 Hirayama N, see Sakai K (2007) 269 233-271 Hirst AR, Smith DK (2005) Dendritic Gelators. 256 237-273 Holzwarth AR, see Balaban TS (2005) 258 1-38... 

Ihmels H, Otto D (2005) Intercalation of Organic Dye Molecules into Double-Stranded DNA - General Principles and Recent Developments. 258 161-204 Iida H, Krische MJ (2007) Catalytic Reductive Coupling of Alkenes and Alkynes to Carbonyl Compounds and Imines Mediated by Hydrogen. 279 77-104 Imai H (2007) Self-Organized Formation of Hierarchical Structures. 270 43-72 Indelli MT, see Chiorboli C (2005) 257 63-102 Inoue Y, see Borovkov VV (2006) 265 89-146 Ishii A, Nakayama J (2005) Carbodithioic Acid Esters. 251 181-225 Ishii A, Nakayama J (2005) Carboselenothioic and Carbodiselenoic Acid Derivatives and Related Compounds. 251 227-246... 

The inter- and intramolecular catalytic reductive couplings of alkynes and aldehydes recently have experienced rapid growth and are the topic of several recent reviews.5 h-8k 107 With respect to early transition metal catalysts, there exists a single example of the catalytic reductive cyclization of an acetylenic aldehyde, which involves the titanocene-catalyzed conversion of 77a to ethylidene cyclopentane 77b mediated by (EtO)3SiH.80 This process is restricted to terminally substituted alkyne partners (Scheme 53). 

Table 22.5 Catalytic reductive coupling of 1,3-cyclohexadiene with alkyl, aryl and heteroaryl a-ketoaldehydes.

For use of alkenes as nucleophilic partners in catalytic reductive couplings, see ... 

Catalytic reductive coupling of epoxides (82, R1 = alkyl) with aldehydes (83) yields /3-hydroxy ethers (84), in a C-0 bond-forming process involving yields up to 90%.311 The reaction is catalysed by (Ph3P)3RuCl, a species which cannot reduce the aldehyde... 

In the presence of a catalytic amount of SbClj-AgSbFg or PhsC+SbFg, the ringopening rearrangement of epoxides proceeds to generate carbonyl compounds, which subsequently undergo catalytic reductive coupling wifh alkoxysilanes-EtaSiH to yield unsymmetrical ethers (Scheme 14.29) [69]. 

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