Alkenes combine with carbon monoxide and hydrogen in presence of octacarbonyldicobalt as catalyst un — Hydrocarbons Chemistry Question

💡 Solution & Explanation

# Hydroformylation Reaction **Step 1: Identify the reaction type** Alkenes react with $CO$ and $H_2$ in the presence of $Co_2(CO)_8$ catalyst. This is the **hydroformylation reaction** (also called the oxo process). **Step 2: Reaction conditions and mechanism** - Catalyst: $Co_2(CO)_8$ (octacarbonyldicobalt) - High temperature (~100-200°C) and high pressure (~100-300 atm) - This generates active cobalt hydride species that adds to the alkene **Step 3: Product formation** The mechanism involves: 1. Insertion of alkene into Co-H bond 2. Insertion of CO into the resulting Co-alkyl bond 3. Hydrolysis to release the carbonyl compound **For example:** $\ce{CH_2=CH-R + CO + H_2 ->[Co_2(CO)_8] CH_3-CHO + CH_3CH_2CHO}$ **Step 4: Major product** The **primary aldehyde** $\ce{R-CH_2-CHO}$ is the major product (via Markovnikov-type regioselectivity favoring the linear isomer under these conditions). **Answer: Aldehydes** (or more specifically, **primary aldehydes/alkanals**) This reaction is industrially important for synthesizing aldehydes, which are then converted to alcohols, carboxylic acids, or other derivatives.