Hydrofunctionalization

In the framework of Frustrated Lewis Pairs, Erker also investigated the hydroboration of a-alkenyl-phosphines with HB(C6F5)2.52/53 Starting from dimesityl(vinyl)phosphine, the CH2CH2-bridged PB 40a was first 

Compounds 39b-d have been characterized by multinuclear, 31P, 11B), UV-vis, and elemental analyses. 

9-BBN 9-borabicyclo[3.3.1 ]-nonanyl Beat catecholboryl Bpin pinacolboryl 

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Although ruthenium and Group 6 metal catalysts are commonly employed for anti-Markovnikov alkyne hydrofunctionalization (Chapter 10), some interesting rhodium- and iridium-catalyzed methods have also been reported. These can be divided into three groups based on the nature of the incoming functional group ... 

The Trost group has disclosed two methods of rhodium vinylidene-mediated hydrofunctionalization (i) intramolecular hydroalkoxylation of alkynols and... 

To date, the hydrofunctionalization route has mainly been used to prepare PBs. Both conceivable strategies, namely the hydroboration of unsaturated phosphines and the hydrophosphination of unsaturated boranes have been reported (Scheme 25). With dialkyl and diarylboranes, the reactions proceed spontaneously under mild conditions, while the addition of boronates HB(OR)2 is catalyzed by a titanium complex, and the... 

Table 6 Cobalt-catalyzed hydrofunctionalization reactions of olefins...

The mechanism of the cobalt-catalyzed hydrofunctionalizations can be rationalized as follows. Common to all protocols is the generation of a cobalt(III) hydride complex 365C from a cobalt(II) precursor 365 (Fig. 84). A major difference lies in the generation of 365C. In the presence of oxygen (entries 1-14), the reaction starts most likely by oxidation of 365 to Co(III) peroxide complexes 365A... 

Mukaiyama et al. transformed the Co(II)-catalyzed hydrofunctionalizations (see Sect. 5.7) to intramolecular oxidative alkoxyl radical cyclizations by omission of the silane (Fig. 98). 4-Penten-l-ols 417 (R2=H) cyclized in the presence of 20 mol%... 

Significant progress in organolanthanide-catalyzedhydroamination over the last two decades has sparked the interest in the development of analogous catalytic hydrofunctionalization protocols. Catalytic hydrophosphination of unsaturated carbon-carbon linkages offers an attractive atom-economic route to phosphines [87,177], It should be noted that inter- and intramolecular hydrophosphinations are also... 

Z-Enynes are useful synthetic building blocks that can be assembled in an atom-economic fashion by hydrofunctionalization. Future work on this transformation aims to develop further mechanistic insight and use these observations to enhance catalyst development efforts. With a more detailed understanding of the nature of the Zr—C bonded intermediates involved in this transformation and the exact role of the aniline additive, alternative reactivity profiles will be targeted. 

A new cyclization and hydrofunctionalization of 1,6-enynes has also been reported recently [119]... 

Radicaloid insertions of olefins into the Rh H bond of [Rh (TPP)(H)] has been used to obtain Rh —CH2—(alkyl)—Nu// species (NuH = OH, NH) using olefins functionalized with end-on —OH and —NH functionalities. Under basic conditions, intramolecular SN2-type attack of the Nu at the a-carbon atom of Rh —CH2—(alkyl)—Nu yields [Rh (TPP)] and cyclic organic products (—CH2—(alkyl)—Nu—) (see Fig. 47). Protonation of [Rh TPP)] then allows regeneration of [Rh° (TPP)(H)]. The combination of these reactions constitutes a new method for selective intramolecular anti-Markovnikov hydrofunctionalization of olefins with O—H and N—H functionalities (150). In this way, three-and five-membered ring compounds (epoxides, furan derivatives, pyrrolidine derivatives) were readily obtained. Formation of four- or six-membered rings... 

Platinum-catalyzed hydrofunctionalization of unactivated alkenes with carbon, nitrogen, and oxygen nucleophiles in synthesis of heterocycles 07CC3607. 

The roles of NHC complexes of copper, silver, and gold in conjugate additions, allylic alkylations, reduction, boration, hydrofunctionalizations, hydrations, cross-couplings, and enyne cycloisomerization have been discussed. ... 

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