MATTESON Boronic Esters

D. S. Matteson, Boronic Esters in Stereodirected Synthesis, Tetrahedron 1989, 45, 1859- 1885. 

Scheme 32 summarizes Matteson s synthesis of serricornin [(4S,6S,7S)-21], the female sex pheromone of the cigarette beetle (Lasioderma serricorne) via boronic esters [55]. Due to the highly stereoselective nature of boronic ester chemistry, this synthesis of 21 was quite efficient. 

In further studies, Matteson et a/.10,11 reported relative rates of substitution of various boronic esters by mercuric chloride details are given in Table 3. The solvent used was a mixture of ethanol (88 %), water (8 %), and glycerol (4 %), buffered with sodium acetate and acetic acid, and reactions were run in the presence of added sodium chloride. Under these conditions, the kinetics of reaction of benzylboronic ester with mercuric chloride were found to obey the rate law... 

Second-order rate coefficients for the reaction of some boronic esters with mercuric chloride in methanol were reported by Matteson and Allies13 details are in Table 4. The solution was buffered with sodium acetate/acetic acid, and the observed rate equation was found to be... 

Matteson, D. S. a-Halo boronic esters intermediates for stereodirected synthesis. Chem. Rev. 1989, 89, 1535-1551. 

Matteson, D.S. (1989). Boronic esters in stereodirected synthesis. Tetrahedron Report No. 250, Tetrahedron, 45, 1859-1885. 

Recently, Matteson and his co-workers have demonstrated interesting boronic ester homologation with very high chiral selectivity and its use in syntheses of natural products 220 . 

An important feature of the boron ester homologation reaction is that the boronic ester product E can itself be used as a starting boronic ester so that the cycle can be repeated to introduce a second chiral center. Matteson has used this methodology to synthesize insect pheromones and sugars. 

Matteson and coworkers have described the deprotonation and alkylation of bis(l,3,2-dioxaborin-2-yOmethane (11). Deprotonation with LiTMP yields the stabilized anion, which can be alkylated with a variety of primary alkyl halides. Oxidation under basic conditions then unmasks the carbonyl group. Matteson has also described the deprotonation of some substituted boronic esters (12 X = SPh, SiMei). - The alkylated products derived from (12 X = SPh) can be treated with A/-chlorosuccinimide under mild basic conditions to yield either the monothioacetals or the acetals. Boron-stabilized carbanions can also be generated by transmetallation of the organostannanes. ... 

This methodology has been developed by Matteson and coworkers, with particular emphasis on chiral boronic esters derived from pinanediol. Sequential chiral centers can be assembled by an iterative procedure with excellent enantiomeric excess at each step. The two chiral centers in eldanolide (37), for example, were assembled in this manner (Scheme 36). ... 

The two contiguous stereocenters present in the aldehyde 155 were installed in a straightforward manner and with an extremely high stereoselectivity using the dihalomethyllithium insertion method of Matteson (Scheme 3) [157]. The (-i-)-pinanediol boronic ester derivative... 

Both Brown and Matteson have made substantial contributions concerning the one-carbon homologation of boronic esters e.g (146) using either LiCf Cl or LiCHC - Both research groups have now reported additional progress in the area and new procedures have been... 

The use of optically pure a-chloroalkyl boronic esters as electrophiles, e.g. the dicyclohexyl boronate 18 obtained from Matteson s elegant methodology [41], lends access to a-alkyl substituted allylboronates (e.g., 19) with very high diastereomeric purity by way of a net inversion of configuration (Equation 9) [42]. Likewise, alkenylmetal fragments react with chiral dichloromethylboronate 20 to afford optically pure a-chloroallylboronates such as 21 (Equation 10) [43]. Subsequent addition of these a-substituted reagents to aldehydes is highly stereoselective. Furthermore, the chloride... 

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